This paper introduced a multiple charge extraction with bias-flip (MCEBF) interface circuit for piezoelectric energy harvesting (PEH). It extracts electric charges on the piezoelectric element with multiple steps and flips the residual charge with bias-flip action. MCEBF not only reduces the dissipation in the equivalent series resistance (ESR) but also enlarges the extracted energy. The effectiveness of MCEBF is studied theoretically. In experiment, an improvement of 57.3$\%$ more harvested power is obtained, compared with the synchronous electric charging extraction (SECE).