The size of the microhotpaltes based on MEMS is micron-grade, typically rectangular membrane of 270μmχ70μm, in micropellistors. Coating catalytic materials on the microhotplate appeared to be an extremely critical step in practice. We report a promising approach for coating catalytic materials on the microhotplate of micropellistors in the paper. A catalytic material coating apparatus was established according to the Technology of Micro-Fluidics Digitalization. In this apparatus, the catalytic materials, finely dispersed A1 2 0 3 suspension and platinum palladium catalyst, were ejected out a micro-nozzle by the pulse inertia force produced by a piezoelectric actuator. The micro-nozzle is fabricated by glass heat process and has the advantages of won't being corroded after being exposed in air for long time, won't pollute the chemical solution in it and being of low cost. The porous A1 2 0 3 matrix thickness and the amount of catalyst can be controlled accurately in this apparatus. The micropellistor with original signal of 75mV was fabricated in this paper and 36m V was remained after aging treatment. The power consumption can remain 75mW as well.