The invention discloses an increment 
ionosphere refraction error 
correction method which is applied to a GNSS single-frequency user. The method comprises a monitoring 
station utilizes 
ionosphere model parameters broadcasted by a GNSS 
system itself to calculate 
ionosphere vertical TEC1, and meanwhile, utilizes double-frequency 
observation data to calculate ionosphere vertical TEC2, and difference value [
delta] TEC between the TEC1 and the TEC2 is obtained; a plurality of monitoring stations transmit the [
delta] TECs of themselves to a master control 
station through a 
communication link; the master control 
station receives each [
delta] TEC, establishes an ionosphere increment variation model, obtains ionosphere increment variation model broadcast parameters a, b and c in a region, and transmits and broadcasts the a, b and c to the user through a broadcast link; a user 
receiver receives a navigation 
signal and the a, b and c, utilizes the ionosphere 
model parameters broadcasted by the GNSS 
system itself to calculate TEC <GNSS>, utilizes the a, b and c to estimate optimum 
estimation value (shown in the specification ) of the ionosphere increment through a common 
Kriging algorithm, and adds the TEC <GNSS> with the optimum 
estimation value (shown in the specification ) to obtain TEC ; and the TEC  is utilized to calculate ionosphere addition time 
delay, so that high-precision ionosphere 
refraction error correction for the GNSS single-frequency user is realized.