Abstract: In order to obtain the experimental data which was high-precision, continuity and from the same sample for establishing dynamic models to simulate the growth and development of cucumber in greenhouse. Aiming at researching the dry weight of cucumber fruit in greenhouse by rapid non-destructive testing (RNDT), with the experiment data of cucumber fruit under four kinds of nutrient solution concentration, a simulation model of dry weight was developed based on the relationship among dry weight，fresh weight and fruit volume. The results showed that the determination coefficients (R2) under four kinds of nutrient solution concentration between the predicted values and the measured values were 0.987, 0.993, 0.925, 0.96 respectively, and the root mean squared error (RMSE) under four kinds of nutrient solution concentration between the predicted values and the measured values were 0.281, 0.607, 0.616 and 0.502 respectively. The predicted values were consistent with the data of experiments. So dry weight of any cucumber fruit are non-destructively, simply, quickly and accurately predicted with this model and this model can provide reference for establishing models of dry mass allocation of cucumber in greenhouse.