A C band thin film bulk acoustic resonator(FBAR) filter packaged by WLP was developed in this paper. The one-dimensional Mason equivalent circuit model was used to design the resonator, the HFSS was used to optimize the electromagnetic packaging model, and then the filter was simulated and optimized in ADS to obtain the stepped FBAR filter. FBAR filter chip was fabricated by cavity structure, and WLP was carried out by taping and electroplating on FBAR bare chip. The test results showed that the center frequency of the filter was 6.09 GHz, the center insertion loss was 2.92 dB, the passband insertion loss was 3.4 dB, the bandwidth was 112 MHz, and the out-of-band rejection was greater than 40 dB.