The invention discloses an operation method for a parallel vertical three-dimensional parking garage. The operation method includes the following steps: S1, a step of garage selecting, namely the stepof selecting a parking case body that a vehicle needs to enter and leave; S2, a step of cyclic garage moving, namely the step of performing cyclic garage moving until the parking case body that the vehicle needs to enter and leave is selected, and directly entering step S3 if the selected parking case body that the vehicle needs to enter and leave is in a ground floor initial position in a groundfloor frame; and S3, a step of the entering and leaving of the vehicle, namely the step of entering and leaving the parking case body in the ground floor initial position in the ground floor frame, wherein the direction of the entering and leaving of the vehicle is consistent with the length direction of the parking case body and vertical to the plane where the circulating moving direction of theparking case body is located. Through the cooperation of garage selecting, cyclic garage moving and the entering and leaving of the vehicle, the parking and picking up of the vehicle can be realized;and the operation method is simple, so that the time of picking up the vehicle can be greatly reduced, and the operation method has obvious advantages.