This should consider the relationship between room space and lighting effect. Soft and clear lighting depends on the cooperation between lampshade and bulb. The intensity of light bulb will affect people's visual effect, vision protection and physical and mental health. Secondly, considering the room space and lighting brightness, the light bulb power is too large to waste electric energy, which is easy to heat up and may cause various accidents; The optional power is too small to achieve better lighting effect. Usually, the lighting in the bathroom is 2 watts per square meter; 3 watts per square meter is enough for dining room and kitchen, and 4 watts per square meter is bigger for study and living room; Lights on desks and nightstands can use 15 to 60 watt bulbs, preferably not more than 60 watts. About 40 to 50W is enough for the bedroom, 40W for the study, 60W to 80W for the living room, 20W for the bathroom and 30W for the kitchen. The above is not absolute, but also related to personal preferences, as long as you are absolutely suitable.