Abstract: Considering the positive effects of plastic-film mulch and negative impacts of plastic film residue synthetically, the evaluation model of effect of plastic-film mulch on crop yield was constructed. Using the experimental data and investigation data of Hubei province, the effect of plastic-film mulch on crop yield was evaluated based on the model. The results show that the yield reduction rate caused by plastic film residue will be greater than the yield increasing rate caused by plastic-film mulch after 36 years using plastic-film mulch techniques. If the negative effects of plastic film residue on crop yield lasted another 16 years, the reduction of yield will be equal to the total increasing yield cased by plastic-film mulch techniques. That is to say, the use of plastic-film mulch is uneconomic under existing plastic film collecting technology in the long run.