During the AC voltage withstand test, the voltage along the long distance submarine cable would be increased due to the capacitance effect. The elevated voltage value is related to the cable length and the test power supply frequency. Under extreme conditions, this value might threaten the withstand voltage level of cable and hinder voltage withstand test. In this paper, a distributed parameter equivalent circuit model considering cable sheath is established to study the cable terminal voltage. Based on this model, the calculation formula of the voltage along a single core cable is obtained. Then the obtained formula is verified by a simulation. Furthermore, the relationship among the voltage along the cable, the cable length and the power frequency is explored. Research results indicate that, the influence degree of test voltage frequency on the voltage along cable increases with the increasing cable length. Finally, a new frequency scope limitation of withstand test source is proposed for the 220 kV crosslinking polyethylene cable with different lengths to restrict the terminal voltage amplitude. It provides some guidance to field test designers.