Abstract: There is a high correlation between dielectric constant and moisture content, and drying process moisture content of agricultural products can be predicted by measuring their dielectric characteristic parameters．High voltage pulse electric fields can effectively accelerate drying process, but influence mechanism of dielectric constant and moisture content in this process still needs further research．In order to solve problem of unclear micro explanation of relationship between dielectric constant and moisture content of fruits and vegetables, taking apples as research object, an effective model was established for relationship between moisture content and dielectric constant of apples, their internal electric field parameters in three dimensions was simulated, Monte Carlo method was used to theoretically simulate and calculate dielectric properties of apples under high-voltage pulse electric fields, and macro and micro media inside apples was treated as lumped parameters to effectively replace their overall internal structure．Experimental results showed that when correction coefficient was 8.96, relative water content of apple was gradually reduced from 88% to 18%, and relative error between calculated and measured values of dielectric constant was stable within 10%．The study could provide a theoretical basis for processing of fruits and vegetables using pulsed electric fields．