The photometric stereo system can easily determine the surface orietation and relative depth of objects

but can not determine absolute depth. In order to determine absolute depth

this paper proposes an algorithm

this algorithm can obtain a needle map respectively by each camera of binocular photometric stereo system first

then solve disparities between the corresponding areas in two needle maps

finally combine disparities correctly

match them accurately and reconstruct 3-D depth of the object surface. This method is highly important for us to develop further exploring research on 3-D surface depth reconstruction and recovery of scene structure.