Spin momentum locking is a key feature of the topological surface state, which plays an important role in spintronics. The electrical detection of current-induced spin polarization protected by the spin momentum locking in non-magnetic systems provides a new platform for developing spintronics while previous studies were mostly based on magnetic materials. In this study, the spin transport measurement of Dirac semimetal Cd3As2 was studied by the three-terminal geometry, and a hysteresis loop signal with high resistance and low resistance state was observed. The hysteresis was reversed by reversing the current direction, which illustrates the spin-momentum locking feature of Cd3As2. Furthermore, we realized the on-off states of the spin signals through electric modulation of the Fermi arc via the three-terminal configuration, which enables the great potential of Cd3As2 in spin field-effect transistors.