The invention discloses an SCR denitration 
system ammonia spraying optimization method based on weight valve regulation and control. The method is divided into four steps: measurement of 
flue gas flow field characteristics, analysis of 
flue gas flow field regional flow characteristics, determination of 
ammonia spraying weight valves and pertinence adjustment of opening degrees of the 
ammonia spraying valves. The method comprises the particular steps: firstly, measuring the 
flue gas flow field characteristics of a flue transverse section in front of an ammonia spraying grille of an SCR denitration 
system under a condition of 
constant load; then combining with a distribution condition of spray nozzles of the ammonia spraying grille, and analyzing 
flue gas flow field regional flow continuous distribution characteristics matched with the ammonia spraying spay 
nozzle distribution; according to the 
flue gas flow field regional flow characteristics under various load conditions, obtaining the weights of the ammonia spraying valves; and finally, adjusting the opening degrees of all the valves according to the valve 
weight difference, simultaneously, with the help of a 
flue gas analyzer, measuring the 
NOx outlet concentration on an outlet section of the SCR denitration 
system, and timely feeding back the adjustment effect of the opening degrees of the ammonia spraying valves. The method can ensure good 
ammonia nitrogen mixing equivalent ratio, effectively improves the denitration efficiency, decreases the ammonia escape and reduces the ammonia amount.