The invention relates to a reconfigurable microwave low-pass filter containing an MEMS switch and the preparation thereof. The filter is an integrated circuit which is produced on a substrate of a high-resistance silicon wafer, an inductive reactance element is composed of a CPW ground wire and a signal wire; on one hand, the MEMS switch constitutes a capacitive reactance element, on the other hand, the MEMS switch leads the frequency of the filter to be adjustable by changing the length of the coplanar waveguide by the switching-on and off. The filter takes the high-resistance silicon wafer as the substrate, uses the process which is compatible with the IC process to evaporate a titanium layer and a gold layer by thermal oxidation, carry out the positive photoresist lithography, the electroplating and the negative photoresist lithography, corrode the gold layer and the titanium layer, remove a negative photoresist, lead a silicon nitride film to grow, remove the silicon nitride film,evaporate and deposit an aluminum-silicon alloy film, corrode the aluminum-silicon alloy film to form a bridge film, remove a sacrificial layer, and the like, for the preparation, and the filter has the advantages of compact and simple structure, small size, good isolation, low insertion loss, low power consumption of a control circuit, high working frequency, compatibility with the traditional IC process and low cost, and is applicable to mass production.