Abstract: A new multi-mode Wilkinson power divider circuit is designed. The traditional Wilkinson power divider was combined with a limited number of single-pole single-throw switches(SPST). The Wilkinson power divider with SPST has two work modes, one is Wilkinson power divider and the other is transmission line mode, by control the SPST. At the same time, the Wilkinson power splitter with multi-modes of arbitrary power division ratio was theoretically analyzed, and the effect of each electrical length of the microstrip line on the performance, such as insertion loss and return loss,of the transmission line mode was verified using the Keysight's ADS simulation tools, and the performance of the Wilkinson power splitter in multiple working modes under the equal division condition is verified.