A millimeter-wave bandwidth reconfigurable broadband pass filter based on Liquid Crystal(LC) material is designed according to LC's good dielectric properties and tuning ability in millimeter-wave band. The filter is composed of a high-pass filter and a low-pass filter to achieve the band-pass effect and loads liquid crystal materials in the low-pass part. Bandwidth reconfiguration is achieved by tuning the equivalent dielectric constant of liquid crystal materials to change the response frequency of low-pass filters. The simulation results show that when the dielectric constant of the tunable liquid crystal is from 2.4 to 3.8, the high cut-off frequency of the filter has decreased from 2 GHz to 48 GHz, the relative bandwidth has changed from 84.9% to 78.3%.