Relaxor based xPb(In1/2Nb1/2)O3–(1-x-y)Pb(Mg1/3Nb2/3)O3–yPbTiO3 single crystals [PIMNTx/(1-x-y)/y] have broader temperature usage range and comparable piezoelectric properties to (1-x)Pb(Mg1/3Nb2/3)O3–xPbTiO3 crystals. In this work, electric-field-induced strain behavior of PIMNT crystals with different orientation and composition was investigated. High strain with low hysteresis was observed in rhombohedral PIMNT25/44/31 crystal oriented along 〈001〉, rather than 〈011〉 and 〈111〉. Ultrahigh strain level up to 0.75% with linear curve can be achieved under 5 kV/mm electric field. The electric field induces phase transformation of PIMNT crystals is much higher than that of PIMNT crystals. These properties make PIMNT crystals promising candidate for high performance solid-state actuators.