The invention provides an extrusion forming method for producing instant vermicelli. The method includes the steps of: preparing raw materials, conditioning pulp, forming by extrusion, vertically hanging, aging with refrigeration, unfreezing with spray, cutting, drying into final product and the like. The aging method of vermicelli according to the invention is easy and highly efficient, and the traditional semi-automatic production is changed into industrial automatic production, which saves a large amount of time, reduces manual labor intensity, improves production efficiency and reduces occupation of field. The technique of the invention is provided with reasonability and high qualification rate which greatly reduces the cost. The water content of the unfrozen vermicelli is low, and the water content of the dried vermicelli is below 12%, thereby providing perfect food safety. The convenient food of vermicelli series prepared according to the method of the invention is provided withcrystal appearance, high transparence, boiling-endurable, chewiness, and good taste, which is a break through in vermicelli process field.