Abstract: Principle component analysis technique was used to analyze large amount of bits utilization data. Utilization effects of bits were evaluated according to the composite appraisal standards established based on 4 factors including cost per meter, footage, penetration rate and well depth. This method, although being similar to the appraisal method of cost per meter, can reveal the potential benefits of bits. It has been used to evaluate and optimize the bits that were used in drilling of Shahejie Fm in Pu-cheng block, Zhongyuan oilfield, and several types of bits with good utilization effects were selected. Preliminary field application has achieved good economic benefits.