The invention discloses a performance evaluation method for a vehicle-mounted remote-control key system. The method comprises: a test area is selected, one point is drawn on the circumference using the theta-degree circumferential angle as an interval at an L-meter interval, wherein the theta is a positive number; among drawn (360/theta) separation lines, a point at a distance of d3 meters to an original point o at each separation line is used as a reference point; a tested vehicle is driven to a test placed, so that the vehicle center is overlapped with the original point o; a farthest distance d4i for realizing normal delocking and locking of a vehicle door based on remote control at the angle is tested at a theta-degree interval, wherein the i is an integer and is larger than or equal to 1 and is less than or equal to (360/theta); and a farthest point dmax and a nearest point in dmin are selected in the d4i and an index for evaluating the performance of a vehicle-mounted remote-control key system is calculated. Therefore, no an anechoic chamber or other expensive laboratory equipment is needed; and evaluation testing is completed with low costs.