Enhancing photoelectric sensitivity of semiconductors is meaningful to develop novel photoelectric materials but still challenging for a pristine semiconductor. Here we increase the crystal plane orientation ratio for higher hole mobility to enhance the surface photovoltage of n-type Bi2WO6 depending on the anisotropy of hole mobility. A strategy of hydrothermal synthesis and post-heating is adopted to prepare Bi2WO6. The diffraction peak relative intensity of (200) crystal plane in Bi2WO6 increases with the post-heating temperature from 200 to 400 °C and then decreases. The surface photovoltage of nano-sheet Bi2WO6 is enhanced to the maximum and then decreased with the diffraction peak change of (200) crystal plane. Theory calculation shows the hole effective mass of the crystal with (200) crystal plane is smaller than that of (113), indicating the higher hole mobility in (200) plane which contributes to the enhanced photovoltaic response. The investigation paves a way to enhance the photovoltaic properties of semiconductors by increasing the hole mobility depending on surface photovoltaic technology facilely.