One of the important requirements for converter steelmaking is to accurately calculate the amount of lime added based on the conditions of hot metal and the requirements of molten steel， in order to avoid waste of flux. However， due to the fast pace of converter production and multiple influencing factors， it is difficult to accurately determine the amount of lime added. In order to accurately calculate the amount of converter lime， avoid lime waste and reduce unnecessary steelmaking cost， mechanism model， classification model and multiple linear regression model are established to calculate the amount of converter lime. Compared with the three models， the pure mechanism model has low calculation accuracy and is difficult to be directly applied to field production. According to the classification model optimized by mechanism model， only 60% of the furnace times difference is less than 500 kg/ furnace. A multiple linear regression model is established using SPSS， and the relationship between lime addition amount and other parameters is obtained

W

Lime

=4 147.24×

w

TSi

+529.67×

w

TC

+60.20×

W

qf

+0.405×

V

O

-1 833.95. The verification results show that， 93% of the calculated difference of the furnace is less than 400 kg/ furnace， 77% of the calculated difference of the furnace is less than 300 kg/ furnace， which can basically meet the requirements of field use. After the model is applied in the field， the amount of lime added is effectively reduced.