The complex terrain and sparse weather stations lead to limited precipitation measurement materials in mountainous areas, and satellite precipitation monitoring is an effective supplement for precipitation information. Selecting the Taihang Mountains as the study areas and taking precipitation data from rain gauges of the national meteorological stations as the reference, the quality of merged percipitation monitoring product developed by national meteorological information center of China were evaluated using the continuous statistical metrics (R, RMSE and RB) and categorical statistical metrics (POD, FAR and CSI), and the relationship of elevation, slope and slope direction with product performance was also discussed. The result showed that the merged product had a high correlation (R>0.7) with the measured data; however, it had higher RB and RMSE compared with non-merged product. Meanwhile, the merged product showed a significant improvement in precipitation detection capability. The POD of whole-sequence diurnal scale reached 0.65 and the FAR was 0.33. Particularly, merged product had better performance in detecting summer precipitation (POD=0.76, FAR=0.32, CSI=0.56). Elevation had a significant (p<0.05) influence on the accuracy and precipitation detection ability for both products. The regression analysis showed that there was a performance turning point in the slope range of 20° to 30°. Both merged and non-merged products performecl poorly on the south slope. In general, after the calibration of rain gauge data, the accuracy and precipitation detection ability of the merged product have been significantly improved, which can reflect the precipitation distribution characteristics of Taihang Mountains correctly.