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In this paper, we employ the finite element
method based on hybrid element technique and develop a
boundary condition and a corner condition to simulate the
acoustic wave propagation numerically. The hybrid
element technique uses both of the triangular and
rectangular elements to dissect the computational area with
rugged surface and extend the mass and stiffness matrices
of triangular element to those of rectangular element in
form for computational unity. In order to eliminate the
boundary reflection on the boundary and at corner better,
we introduce a boundary condition which contains a
parameter, the incident angle, and develop a corner
condition which considers both of the up or down going
wave and lef t or r ight g oing w ave. V ery encouraging
results have been obtained on theoretical and real models .