To achieve the goals of “carbon peak” and “carbon neutrality”, a type of new power system with increasing proportion of renewable energy needs to be built. The significant characteristics of the new power system include a high proportion of renewable energy, a high proportion of power electronic equipment, and a high proportion of new load, which will result in significant changes in the load characteristics of the power system. First, the changes in power load are summarized from the perspectives of total load and load composition, and the research challenges faced by load models are analyzed. Then, the power-electronic-interfaced load models and the generalized load models with distributed generations are introduced from both the mechanistic and non-mechanistic model perspectives, pointing out the need for further research. Finally, in response to the new simulation requirements for the new power system, three types of specialized load models are presented, namely, electromagnetic transient load model, short-circuit current load model, and load harmonic model, with suggestions for future research directions.