A movable battery replacing platform includes a travel-driving portion used for driving the movable battery replacing platform to move on the ground; a lifting portion mounted on the travel-driving portion, for lifting a battery during the replacement of the battery; and a battery mounting portion mounted on the top of the lifting portion, for placing a battery to be replaced or a replaced battery. The battery mounting porting is provided with a battery replacing device. The device can use an unlocking device to unlock a battery locked on the bottom of an electric vehicle, automatically aligning an unlocking point of a battery locking mechanism and realizing automatic unlocking in the movement. The angle of an upper board relative to the battery unlocking position can be adjusted by a movement actuating device, so that the unlocking point of the battery can automatically fit where the movable battery replacing platform remains still.