The interface curvature calculation is not accurate in VOF method and the interface mass is not conserved in Level Set method, A new interface tracking method CVOFLS is proposed (Coupled Volume of Fluid and Level Set method). This method combines the advantages of VOF and Level Set, The VOF and Level Set functions are simultaneously solved according to the fluid velocity, The interface obtained by the VOF function is used to correct the fluid quality, The Level Set function is used to calculate the interface norma, The Level Set function reinitialization process is omitted, Thus, the deficiencies of the two methods are overcome effectively. An example of interface tracking numerical simulation shows that, this method can guarantee high precision of free interface tracking and good mass conservation, and it can improve the calculation efficiency.