We first propose a general method to construct the complete set of on-shell
operator bases involving massive particles with any spins. To incorporate the
non-abelian little groups of massive particles, the on-shell scattering
amplitude basis should be factorized into two parts: one is charged, and the
other one is neutral under little groups of massive particles. The complete set
of these two parts can be systematically constructed by choosing some specific
Young diagrams of Lorentz subgroup and global symmetry $U(N)$ respectively ($N$
is the number of external particles), without the equation of motion and
integration by part redundancy. Thus the complete massive amplitude bases
without any redundancies can be obtained by combining these two complete sets.
Some examples are presented to explicitly demonstrate this method. This method
is applicable for constructing amplitude bases involving identical particles,
and all the bases can be constructed automatically by computer programs based
on it.
