For clarifying the impact of applying moisture control bamboo charcoal(BC) as a filler on hygrothermal performance of building component and enclosed space, BC samples carbonized at 600℃ were tested for hygric properties including equilibrium moisture content(u) and water vapor transmission coefficient(δ). Afterwards, 18 exterior walls in 6 typical cities from 3climate zones were constructed in WUFI Plus software for full year simulation. Hygric properties test results show that, compared with 3 bamboo based panels, the moisture control capacity of BC is enhanced when relative humidity is 334%854%. Water vapor transmission coefficient of BC is 932×10-11kg/(m·s·Pa), which is 1002132 times that of the bamboo based panels. The building component and enclosed space simulation results show that BC contributes significantly to improve the moisture content stability of construction layers, weaken the annual moisture and heat flow, and reduce internal surface temperature amplitude of the exterior walls. BC can help reduce the annual amplitudes of the indoor relative humidity and air temperature, shorten the heating, ventilation and air conditioning(HVAC) period, and lower the heating and cooling demand, However, the impact on humidification and dehumidification demand is insignificant.