The passenger compartment of the SEAL remained stable in the frontal offset test. Dummy numbers showed good protection of the knees and femurs of both the driver and passenger. BYD showed that a similar level of protection would be provided to occupants of different sizes and to those sitting in different positions.  Protection of all critical body areas was good for the front passenger and at least adequate for the driver.  Analysis of the deceleration of the impact trolley during the test, and analysis of the deformable barrier after the test, revealed that the SEAL would be a moderately benign impact partner in a frontal collision. In the full-width rigid barrier test, protection of all critical body areas was good or adequate for both the driver and the rear passenger. In both the side barrier test and the more severe pole impact, protection of all critical body areas was good and the SEAL scored maximum points in this part of the assessment.  Control of excursion (the extent to which a body is thrown to the other side of the vehicle when it is hit from the far side) was adequate. The SEAL has a counter-measure to mitigate against occupant to occupant injuries in such impacts and this performed well in Euro NCAP's test. Tests on the front seats and head restraints demonstrated good protection against whiplash injuries in the event of a rear-end collision.  A geometric analysis of the rear seats also indicated good whiplash protection.   The SEAL has an advanced eCall system which alerts the emergency services in the event of a crash.   The car also has a system which applies the brakes after an impact, to avoid secondary collisions.  BYD demonstrated that if the car entered water, the doors, if locked, could be opened within two minutes of power being lost but did not demonstrate the duration for which windows would remain functional.

In both the frontal offset and side barrier tests, good protection was provided to all critical body areas for both child dummies, and the BYD SEAL scored maximum points in this part of the assessment.  The front passenger airbag can be disabled to allow a rearward-facing child restraint to be used in that seating position.  Clear information is provided to the driver regarding the status of the airbag and the system was rewarded.  The SEAL is equipped with a direct 'child presence detection' system, which issues a warning when it detects that a child or infant has been left in the car. However, the system did not meet Euro NCAP's requirements and was not rewarded. All of the child restraint types for which the SEAL is designed could be properly installed and accommodated in the car.

Protection of the head of a struck pedestrian or cyclist was predominantly adequate, with poor results recorded only on the stiff windscreen pillars.  Protection of the pelvis, femur, knee and tibia was at good at all test locations and the SEAL scored maximum points in this part of the assessment.  The autonomous emergency braking (AEB) system of the BYD can respond to vulnerable road users as well as to other vehicles.  Overall, the system performed well in tests of its response to pedestrians, although the performance in certain test scenarios was marginal. The system scored highly in tests of its reaction to cyclists, including dooring, in which the car prevents or warns against door opening if a cyclist is approaching from behind.  Similarly, the AEB system performed well in all tests of its response to motorcyclists and scored full points.

The autonomous emergency braking (AEB) system of the BYD SEAL performed well in tests of its reaction to other vehicles.  A seatbelt reminder system is fitted as standard to the front and rear seats but the driver status monitoring system did not score highly, detecting only driver drowsiness.  The lane support system gently corrects the vehicle’s path if it is drifting out of lane and also intervenes in some more critical situations.  An update in March 2024 is intended to make the lane support system more usable for drivers.  The score in Euro NCAP's tests would be slightly reduced for this part of the assessment but the star rating would be unaffected.  The speed assistance system identifies the local speed limit, and the driver can choose to allow the limiter to be set automatically by the system.