We have solved the Shr?dinger equation of three Fermi ions with coplanar configuration in a Paul trap,when the whole spin angular momentum of the system is S=1/2 or 3/2.The structure and quantum dynamics of this system are investigated by inspecting the wave function nodal structure and the shape-density.At the same time,we compare our result with that of three Bose ions system and three ions system in classical condition.