Aiming at the problem of poor insertion loss and isolation of MEMS single-pole multi-throw (SPMT) switches, a single-pole five-throw (SP5T) MEMS switch was designed to realize balanced signal distribution and low loss transmission through a snowflake power splitter. Simultaneously, the weak contact of the switch was effectively reduced, and the stability of the switch contact was enhanced by designing the H-shaped top electrode structure. The radio frequency and mechanical performance of the designed switch were analyzed and simulated by using HFSS and COMSOL software. The simulation results showed that the insertion loss of the five ports was below 02 dB @20 GHz, the isolation was above 23 dB @20 GHz, and the driving voltage was 24 V. These targets were better than the conventional SPMT switch. The SP5T MEMS switch could be used in multi-task, multi-channel tunable devices, and it had application values in communication and microwave test systems.