In this paper, we present an approach of a new surface tension formulation for Smoothed particle hydrodynamics (SPH). Our method of the surface tension formulation is decomposed into three main processes: (1) mesh smoothing, (2) surface tension computation and (3) surface tension transfer. Firstly, we exploit a Lagrangian operator to smooth an initial three-dimensional discrete interfacial surface mesh generated from the fluid particles using the Marching Cubes method, and then the surface mesh should be scaled in a volume-preserved way and its center should make a translation motion to its original position, thus we gain a new volume-preserved smoothed mesh which is abbreviated as smoothed mesh. Secondly, surface tensions strengths on the vertices of the interfacial surface mesh are computed according to the offsets from the original surface mesh to the smoothed mesh. Finally, we transfer the surface tension strengths above from the mesh vertices onto their neighbor particles of SPH in a conservation way. The proposed approach of surface tension solver is simple and straightforward to be plugged into a standard SPH solver. Experimental results show that it is effective and efficient to produce realistic fluid simulations, especially the phenomena associated with strong surface tension.