The invention aims to provide a liquid state silica gel sizing device. According to the technical scheme, the liquid state silica gel sizing device is composed of a lower mold plate, product implanting grooves, product position clamping blocks, a lower-position silica gel releasing device, an upper mold plate, a silica gel injecting port, a cold runner silica gel dispensing device and a high-position silica gel releasing device; a product fixer is arranged in each product implanting groove, and is composed of a center inserting block, a first edge inserting block, a second edge inserting blockand two fixing bolts; the lower mold plate is provided with positioning columns, auxiliary positioning columns, auxiliary positioning grooves and pressure springs; and the cold rubber silica gel dispensing device is composed of a supporting table, a silica gel entering storing disk, a silica gel injecting rotating disk and a silica gel injecting pipe. The whole mold structure is clear in train ofthought, and operation is convenient; the structural design of the cold runner silica gel injecting type and the structural design of raw material recycling are adopted, the overall machining stability is improved, the shape attractiveness and the production efficiency are improved, raw materials for use are greatly reduced, cost is reduced, the mold is also well protected, and pollution is reduced.