The utility model provides an utensil is examined to injection moulding product size, includes base and determine module, its characterized in that: base one side is provided with a recessed groove, the middle part of the recessed groove left and right sides all is provided with a notch, four corners of recessed groove respectively are provided with a with notch circular port, be provided with determine module on the base of recessed groove one side, determine module includes fixed block and pushing devices, the lower part embedding of fixed block sets up in the shrinkage pool on the base, thefixed block passes through the screw to be fixed the fixed block on the base, one side of fixed block is provided with pushing devices, pushing devices includes a top, two circular posts and set up the ejector pad between two circular posts, circular post, the ejector pad is fixed the setting on the top all, the tip of ejector pad is provided with the plush copper, in the through -hole on one side deepening to the fixed block of circular post, the cover is equipped with the spring on the circular post between fixed block and pushing devices top. The utility model discloses detect fastly, efficient, do not have artifical error, the simple structure, with low costs of detecting.