The invention provides a fixing device for plastic mold processing and relates to the field of plastic mold processing. The fixing device for plastic mold processing comprises a base, wherein one side of the base is provided with a controller; the top of the base is provided with a sliding chute; the sliding chute is internally and symmetrically provided with two sliding blocks matched with the sliding chute for use; the top of each sliding block is fixedly connected with the bottom of a connecting rod; the top of each connecting rod is fixedly connected with the bottom of an infrared sensor; the bottom of each sliding block is fixedly connected with one end of one fixed rod, and the other end of each fixed rod extends into the base; the part, positioned between the two fixed rods, in the base is fixedly provided with a tightening device. The fixing device for plastic mold processing can be used for achieving the purpose of automatic product fixation, avoiding manual adjustment and fixation, greatly saving time and manpower, reducing the labor intensity of operating personnel and improving the product processing efficiency.