The invention discloses an environment-friendly plastic PU (polyurethane) combined forming structure and a manufacturing process thereof. On the one hand, the environment-friendly plastic PU combined forming structure comprises a plastic main framework, a plurality of reinforcing ribs are arranged on the plastic main framework, the periphery of the plastic main framework is provided with a plurality of adhesion holes, a PU layer formed by PU foam is wrapped on the outer surface of the plastic main framework to form an integrated structure, and the PU layer is adapted with the adhesion holes. On the other hand, the manufacturing process for the environment-friendly plastic PU combined forming structure comprises the following steps of: manufacturing the raw plastic particles into colorful plastic particles required by the design, then heating the plastic particles and performing high-pressure injection molding to form the plastic main framework, and taking out the plastic main framework after being cooled; and pouring the PU foam into the plastic main framework to form the integrated structure. The invention has the advantages of capabilities of protecting the environment, avoiding environmental pollution and improving the yield, attractiveness, long service life, use safety and reliability, difficult generation of fragile deformation, low processing cost and the like.