The invention discloses a port self-learning method of a portal crane frequency converter. The port self-learning method comprises the following steps: driving a portal crane to be retained at a first position, and collecting initial level states of multiple input ports at the moment; driving the portal crane to execute first operation from the first position to a second position, and collecting and saving the level states of the multiple input ports in the process; driving the portal crane to be retained at the second position, and collecting the initial level states of the multiple input ports at the moment; driving the portal crane to execute second operation from the second position to the first position, collecting and saving the level states of the multiple input ports in the process, and confirming and saving the position of a port of which the level jumps; judging whether the self-learning operation is successful; and determining switch functions corresponding to four input ports connected with switches, and saving the switch functions as self-learning results. The invention further discloses a portal crane frequency converter. According to the port self-learning method of the portal crane frequency converter, by means of self learning, functions and on-off characteristics of the switches can be obtained, and whether the switches are damaged can be pre-judged.