Aiming at problems of quantitative analysis of low concentration formaldehyde gas in indoor

it is difficult to employ the initial weight sensitivity

easily fall into local extremum of BP algorithm. BP network optimized by genetic algorithm（GA） is improved. 30 groups of formaldehyde ranging of（0. 002

0. 06） × 10-6 is quantitatively analyzed. Optimized weight value threshold is substituted into the BP network

and the regression analysis is carried out.Experimental results show that the running time of the optimized BP algorithm is about 1/2 of the BP network

and its prediction precision is higher than BP network. Compared with BP network

the combination of GA and BP network is more suitable for dealing with quantitative

analysis of formaldehyde gas.