Screw-driving dispensing system is widely applied with the advantages of high precision and extensive use of fluid. Based on the flow rate dynamics model of screw-driving dispensing system，the influences of operat- ing setting time，bulk elastic modulus of fluid and index of non -newtonian fluid on the dynamics of flow rate were analyzed. It is proved that the longer the system operating time is，the more stable the system is；the stronger bulk elastic modulus and index of non-newtonian，the slower the velocity transient response. Comparing simulation results with experiment results，it is revealed that integration of the flow rate can be used to predict the volume of fluid dispensed with the error less than 5%.