Quasi-geoid plays an important role in space exploration,satellite navigation and geophysical engineering construction.After a long period of research,the determination of quasi-geoid has made great progress in model,method and theory; however,there are still some problems existed.For example,though the theory is mature,themethod is not applicable; the accuracy of this model still needs to be improved,especially for small and complex area,which cannot meet the needs of engineering construction.In this paper,after analyzing quasi-geoid theory,quadraticsurface fitting method and support vector machine regression method are compared.The results show that the fitting accuracy of quasi-geoid by support vector machine is significantly higher than quadratic surface fitting method,so,itcan be used in complex small terrain areas for construction projects.