Abstract: As the precision of CQG2000 cannot meet the need of practical work, a residual model method of combining gravity quasi-geoid and GPS level has been presented. Based on CQG2000 and GPS level points with comparatively high density, the JiLin West Quasi-Geoid (JLWQG) is determined by this residual model method. This paper also discussed the triangulation bilinear interpolation algorithm and its applicability for JLWQG. The study shows that the precision of JLWQG is up to ±0.05m. And JLWQG is widely and efficiently used in the renewal of basic surveying and mapping in the west of JiLin.