With the validation of wind-tunnel test, the wind characteristics and temperature distribution under different wall heating conditions in street canyon were investigated by CFD simulation with RNS model using enhanced wall treatment wall function. Result reveal that wall heating scenarios made significant impact on velocity in the canyon. Whole wall heating exert greater influence on velocity than linear heating. Thermal buoyancy arising from the temperature difference between the heated wall and air in canyon have greater impact on velocity near the canyon walls. Windward wall heating decreased velocity and leeward wall heating increased velocity for most heating scenarios except for horizontal velocity in the middle area of the canyon. This work indicated that thermal buoyancy can also improve pedestrian-level ventilation to a certain extent. Different wall heating scenarios have influence on the temperature field in the street canyon. It also provides a meaningful reference for urban planning.