A systematic calculation method for transient short circuit current is presented for the shipboard medium-voltage (MV) power grid with high resistance grounding. Considering the transient characteristics of synchronous generator and asynchronous motor, according to the location of short circuit, all generators and motors in the system are equivalent to a generator based on the layered equivalent method. For the equivalent generator, the transient currents under three-phase symmetrical and various asymmetric faults including system distributed capacitance are solved by using symmetrical component method. Simulink simulation results verify the validity and accuracy of the method.