A coolant control valve unit includes: a valve housing including a barrier rib where a coolant path and a fail-safe path are formed, the valve housing further including an exhaust path through which coolant exhausted through the coolant path passes; a valve disposed to open and close the coolant path; an actuator that opens or closes the coolant path by moving the valve; a flow guide extended from the barrier rib, of which an end is formed in a flow direction of the coolant in the exhaust path, and guiding a flow of coolant exhausted through the coolant path and a flow of coolant exhausted through the fail-safe path; and a fail-safe valve closing the fail-safe path by being inserted into the fail-safe path, while opening or closing the fail-safe path by a coolant temperature.