This paper establishes a new finite volume element scheme for Poisson equation on triangular meshes.The trial function space is taken as Lagrangian cubic finite element space on triangular partition,and the test function space is defined as piecewise constant space on dual partition.Under some weak condition about the triangular meshes,the authors prove that the stiffness matrix is uniformly positive definite and convergence rate to be O(h3) in H1-norm.Some numerical experiments confirm the theoretical considerations.