Among many kinds of ways to study the properties of atom and molecule collision, the quasi-classical trajectory (QCT) method is an effective one to investigate the molecular reaction dynamics. QCT calculations have been carried out to investigate the stereodynamics of the reactions F+H_{2}/HD/HT→FH+H/D/T, which proceed on the lowest-lying electronic states of the FH_{2} system based on the potential energy surface (PES) of the 1^{2}A' FH_{2} ground state. Although the QCT method cannot describe all quantum effects in the process of the reaction, it has unique advantages when facing a three-atoms system or complicated polyatomic systems. Differential cross sections (DCSs) and three angle distribution functions P(*θ*_{r}), P(ø_{r}), P(*θ*_{r}, ø_{r}) on the PES at the collision of 2.74~kcal/mol have been investigated. The isotope effect becomes more obvious with the reagent molecule H_{2} turning into HD and HT. P(*θ*_{r}, ø_{r}), as the joint probability density function of both polar angles *θ*_{r} and ø_{r}, can reflect the properties of three-dimensional dynamic more intuitively.