Abstract: Numerical bit drilling simulation is a practical technology that combines bit-rock interaction simulation theory with bit performance evaluation and structure optimization,drilling simulation software was developed to provide technical support for bit design and performance analysis.Based on the existing three-cone bit simulation model,software was developed by MATLAB.This paper especially addresses data input,numerical algorithm and simulation result visualization,etc.It can simulate bit geometry,analyze cone behaviors under ideal conditions and in drilling process in vertical wells,horizontal wells and directional wells,and evaluate relevant physical parameters in rock breaking.It has been applied to bench test optimum teeth arrangement for a certain types of cone bits,with intuitive and quantitative features.It indicates that the software is convenient,efficient and reliable for optimizing bit design.