In order to cope with the declining fishery resources, stock enhancement has become one of the main methods of restocking and maintaining the sustainable use of resources. After the implementation of enhancement, the sustainable characteristics of fishery resources are a problem that scholars generally care about, but can not be effectively solved by using traditional surplus production models. Based on the traditional Schaefer surplus yield model, this study proposed a surplus production model (enhancement surplus production model) suitable for the case of stock enhancement, and simulated and analyzed the effects of different enhancement and fishing strategies on the model. The form of this model is similar to the Schaefer surplus production model, but it adds a parameter describing the growth characteristics of the enhancement stock-the effective enhancement rate (e) to express the impact of the stock enhancement on the yield. The results show that reasonable enhancement quantity can increase the maximum sustainable yield (MSY), and the use of the enhancement surplus production model can obtain reasonable estimates of MSY and other key indicators. Compared with the non-enhancement situation, under the influence of stock enhancement, the biomass required to reach MSY (B_MSY) is small, while the maximum sustainable fishing effort (E_MSY) increased. Inhibition occurs between the existing stock (the stock that originally existed in the sea area) and the enhancement stock reflected in the enhancement surplus production model. Under the influence of this effect, different enhancement and fishing strategies will affect the assessment results of the model. Compared with the traditional model, this model assesses the MSY under the effect of stock enhancement, and improves the accuracy of the results, which can be used to estimate the MSY of enhancement species in well-defined sea areas such as marine ranching.

stock enhancement  /  surplus production  /  maximum sustainable yield  /  effective enhancement rate