The invention discloses a 
chassis battery change 
system for electric passenger cars. The 
chassis battery change 
system comprises a rapid change 
robot, a battery change platform, a transfer platform, a background 
monitoring system, a stacking 
machine and a charging frame, wherein the transfer platform, the stacking 
machine and the charging frame are arranged on one side of the battery change platform; the rapid change 
robot is arranged between the battery change platform and the transfer platform; an electric passenger car is capable of passing through the battery change platform; a 
locking mechanism which corresponds to a battery box supported by the rapid change 
robot is arranged on the electric passenger car; and the background 
monitoring system is connected with the rapid change robot and the stacking 
machine respectively through an 
industrial Ethernet. At the same time, the invention also discloses a using method of the 
system. A mechanical positioning mechanism of the battery change platform is simple, correct in positioning and low in manufacturing cost; a hydraulic lifting mechanism is used in the rapid change robot, so that the whole change process is reliable and stable, the size of the change equipment is decreased effectively and the actual occupied area of the change system is saved; and the transfer platform is used as a battery change interaction link between the rapid change robot and the stacking machine, so that the time spent by the battery change is further shortened.