Each observation station in the VLBI has an independent hydrogen clock.In particular,on rare occasions the phase lock synthesizer loss phase lock on the signal from the hydrogen maser cavity resulting in a discontinuity in the clock time obtained from the maser,this phenomenon is referred to as a “clock break”.Clock breaks can be several hundred nanoseconds.In the VLBI data analysis and analysis to consider the special operation of the clock breaks.In the least squares solution method,it is necessary to reduce the influence of the clock break on the residuals of the observed data and the accuracy of the solution.