The ratio of HPMC’s hydroxypropyl value to methoxy value has a great influence on the water solubility, surface activity and gel temperature of the product. If the methoxy value is high and the hydroxypropyl value is low, the water solubility and surface activity of the product will be better, and the gel temperature will decrease. If the hydroxypropyl value is appropriately increased and the methoxy value is decreased, the gel temperature can be increased, and the water solubility and surface activity can be kept stable. However, if the hydroxypropyl value is too high, the gel temperature will be reduced, the water solubility and surface activity will be weakened, and the solubility in organic solvents will be greatly improved. Therefore, the ratio of HPMC methoxy value and hydroxypropyl value must be comprehensively stabilized according to the requirements of product performance in order to achieve the desired effect.