[Objective] The changes of vegetation net primary production (NPP) and its response to climate factors were quantitatively analyzed to provide scientific reference for assessing the role of urban carbon sequestration under different climate conditions and improving urban ecosystem carbon sequestration. [Methods] Based on GEE (Google Earth Engine), the NPP of Tianjin City during 2001—2022 was calculated, and the spatial and temporal variation pattern of NPP was analyzed by Slope trend analysis, F-test, barycentric migration model, standard deviation ellipse model, and other methods. Multi-factor sensitivity analysis and correlation coefficient evaluation were used to quantitatively evaluate the NPP response characteristics under temperature, precipitation, and wind-speed changes. [Results] ① The average annual vegetation NPP in Tianjin City showed an increasing trend of fluctuation, and the fluctuation range was 53.46—96.54 g/(m²·a) (calculated by C); ② The vegetation NPP of Tianjin City is higher in the north and lower in the south, and higher in the west and lower in the east. The center of gravity is concentrated in the central region, and it gradually moved to the south during 2001—2022. ③ The response of vegetation NPP to climate factors in Tianjin City has a significant lag time of 1 month for temperature and precipitation and 3 months for wind speed. [Conclusion] The variation of NPP in Tianjin City has great spatiotemporal heterogeneity and is affected by temperature, precipitation, and wind speed, with a lag effect of 1—3 months in response to climate factors.