The foundation uplift behavior of sluice is an important index reflecting safety of a sluice. By analysis of quality and quantity, the abnormal reasons are studied of partial old and new piezometric holes located in the Huaan Sluice, the method to judge false abnormality phenomena is analyzed. The research result indicates that abnormal water levels are due to the following conditions: the P7 old piezometric hole was silted up, the impervious curtain in front of P8 and P9 old piezometric holes was weakened or there are some seepage channels between upstream face of sluice and these holes, and construction quality of P1,P7,P8,P9 new piezometric holes was not good enough. These abnormal water levels of piezometric holes not only reflect the environmental, structural and seepage control variation, but also mirror the construction quality