The invention discloses a 
model method for calculating an equivalent uniform dosage of radiotherapy, wherein an LQ model is not fundamentally changed and a 
cell survival condition in a single 
large dose can be well reflected. Effectiveness of original clinical experience is ensured, and the method can be used for effect evaluation of 
large dose irradiation after slight correction of the 
original data. Based on the equivalent uniform 
dose of a segmented secondary 
function model, by means of a formula, a treatment planning 
system can quickly acquire the equivalent uniform doses of a tumor and anormal organization, thereby facilitating 
comparative evaluation of treatment plans with different 
dose segmentation 
modes and different 
dose distribution patterns. The segmented secondary 
function model is used for 
settling a problem of 
high cell survival rate prediction deviation after performing large-dose 
irradiation by a traditional linear secondary model. The equivalent uniform dosage modelbased on the model realizes comparison of the treatment effects in different dose distributions. After introducing latent 
doubling time, the advantages of single large-dose 
irradiation at an aspect ofovercoming 
cell proliferation is presented, and a difficulty in clinical application of a 
radiation biological model is basically solved.