The triethanolamine (TEA) with different concentrations was added to the slurry to lap of quartz crystal. By defining the ratio of Material Removal Rate(MRR) and Pad Wear Rate (PWR) as the wear ratio, the effects of TEA concentrations on the magnitude and stability of quartz crystal, MRR, PWR, wear ratio, Friction Coefficient (COF), Acoustic Emission (AE) and the surface quality of quartz crystal after lapping were investigated in fixed abrasive lapping process. The results show that with increasing additive amount of TEA in the slurry, the wear ratio increases first and then decreases, and the magnitude and stability of MRR for the quartz crystal have the same variation trend, too. Moreover, the COF decreases first and then increases and AE increases first and then decreases. The surface quality of quartz crystal after lapping gets first better then goes bad. When TEA concentration is 5%, the MRR of quartz crystal is the maximum and most stable, and the service life of FAP is the longest and surface quality is the best. Obtained results indicate that to add appropriate amount of TEA in the slurry will stabilize the lapping process of quartz crystal, prolong the service life of pad, enhance the surface quality of work pieces and reduce production costs in lapping process.