The influences of isotopic variant and collision energy on the stereodynamics in the N(4S)+H2 reaction are investigated by using the quasi-classical trajectory method on the calculated DMBE potential energy surface. The angular distributions of P(r), P(r) and P(r, r), which reflect the vector correlation of k-j' and k-k'-j', differential cross sections,integral cross sections are calculated and discussed in detail. Moreover,the influences of collision energy variant in a collision energy range of 25-80~kcal/mol in the three reactions N+H2,N+D2 and N+T2 are also studied The results indicate that the stereodynamic properties of the reactions are influenced by intermolecular isotope and collision energies.