In ecological risk assessment, mechanistic effect models (MEMs) are thought to overcome the limitation of standard laboratory single species test by accurately extrapolating the models to population-level. This review introduces the basic theory of MEMs-dynamic energy budget theory which can connect with toxicokinetic/ toxicodynamic models to describe the interaction of toxicants and organisms. This review summarizes some typical MEMs which simulate different scenarios, pesticides and species, and compared their modelling performance according to the guidance on good effect models of European Food Safety Authority, in order to judge if it is accounting for all modelling steps. In addition, a summary of the linkage of MEMs in pesticides ecological risk assessment have been discussed, especially evaluating the linkage results of ‘MODELINK’ workshop. However, there is no genuine application of MEMs in pesticides ecological risk assessment in real world today, because there is no validated model built with acceptable predictive power to motivate the ecological assessors or shareholders to use effect models confidently. Therefore, there is still a long way to develop an effect model which is valid enough and has strong prediction power.