The characteristics and difficulties of the time logarithm method for calculating the coefficient of consolidation have been analyzed. The VBA programming method for calculating T50 and coefficient of consolidation have been designed. A convenient method for calculating T50 and coefficient of consolidation is presented. Through the analysis of consolidation test cases, the veracity and convenience of VBA programming method are illustrated. It provides a reliable method for calculating the coefficient of consolidation in consolidation test. At the same time, the advantages, disadvantages and applicability of time logarithm method and time square root method are analyzed. Time logarithm method requires higher quality of the tail of the curve, and time square root method requires higher quality of the initial section of the curve. It is suggested that the time logarithm method be used to solve the coefficient of consolidation for the initial data collection of the deformation-time curve. It is suggested that the time square root method be used to solve the consolidation coefficient for the unideal consolidation test data collection of the tail data of the deformation-time relation curve.