The invention relates to the field of circuit breaker assembly equipment, and in particular to a circuit breaker assembly method and a circuit breaker assembly trolley. The circuit breaker assembly method comprises the following steps of 1) positioning and fixing a sealing plate of a circuit breaker on the circuit breaker assembly trolley by matching of an installation hole in the sealing plate of the circuit breaker; 2) respectively arranging a mechanism module and a pole post module at two sides of the sealing plate, additionally arranging a secondary fixing device, and positioning the circuit breaker which is assembled by matching of the secondary fixing device and the mechanism module; 3) sending the circuit breaker which is assembled in the step 2) to an installation position by the circuit breaker assembly trolley, removing the fixing of the sealing plate, and maintaining a fixing effect of the secondary fixing device; 4) fixing the sealing plate and a corresponding case; and 5) removing the secondary fixing device, and withdrawing the circuit breaker assembly trolley. By directly assembling each module of the circuit breaker on the circuit breaker assembly trolley, the circuit breaker which is assembled is not needed to install on a transfer trolley, the assembly time is saved, and meanwhile, the assembly efficiency is also improved.