An anti-dust device for a mathematic data processor effectively solves the problems that temperature reduction and dust removal cannot be perfectly integrated and reasonably planned in the prior art. The mathematic data processor includes: a processor, of which a side board has a double layer hollow structure; a dust filter device is built in an inner chamber of the side board; there are a plurality of vent holes, at different positions, formed in inner and outer sides of the side board; hole covers are fixedly installed on the vent holes in the inner side of the side board and are fixed in the vent holes by means of fixers; an air port is formed in each hole cover and is connected to a fan, which is fixed on the fixer, through an air pipe. The anti-dust device has novel structure and reasonable arrangement. Through the double-layer side board with the built-in filter device, the requirement of temperature reduction and dust prevention of the processor can be satisfied at the same time. The positions of the vent holes and fans in the structure can be adjusted according to arrangement of components inside the processor, thereby forming reasonable air channels to dissipate the heat in the processor. The device maintains the processor to be at a constant temperature, thereby guaranteeing stable operation of electronic components.