The present invention relates to a girder formwork, in particular to a formula and a preparation method of a novel building plastic girder formwork, used in the technical field of building materials. The preparation process includes the steps of mixing shutdown material → mixing product material → preheating → feeding shutdown material → feeding product material → feeding → traction by a traction rope → vacuum sizing and cooling → traction by a tractor → cutting → re-feeding shutdown material. The formula and preparation method of the novel building plastic girder formwork of the present invention have good mechanical strength, long service life, impact resistance, resistance to deformation and high recycling value. In particular, it facilitates the comprehensive utilization of waste plastic recycling, reduces construction costs, and is worthy of popularization.

Country Code: CN

Application Number: CN201210272046.X