The present disclosure provides a power extension cord with movable outlet modules, which includes a power input portion, a casing, and a plurality of outlet modules. The power input portion is connected to a city power source. The casing at least includes a first accommodating portion having at least a first sliding track. Each of the outlet modules is electrically connected to the power input portion, and at least one outlet module is movably disposed on the first sliding track. When all the outlet modules are arranged on the first accommodating portion, at least one outlet module becomes immovable on the first sliding track. When one or more outlet modules are dislocated from the first accommodating portion, at least one of the outlet modules becomes movable along the first sliding track. Accordingly, the present disclosure may thus effectively utilize the pin holes associated with each outlet module.