An auto transmission hydraulic control apparatus may include six friction elements that of which two friction elements operate to achieve a corresponding to each stage by hydraulic pressure, five direct-controlled solenoid valves that individually and directly control hydraulic pressure to four friction elements and equally and directly control hydraulic pressure to the other two friction elements, an on-off solenoid valve converting output state and non-output state of hydraulic pressure, a switch valve in which one side of a valve spool is supplied by a spring to selectively supply hydraulic pressure from one of the direct-controlled solenoid valves, equally and directly controlling the hydraulic pressure supplied to the two friction element, in accordance with whether hydraulic pressure from on-off solenoid valve is applied to the other side thereof, and four fail-safe valves disposed between the direct-controlled solenoid valves and the friction elements to structurally limit available arrangements of the friction elements.