A control module of a window shade comprising: an outer casing, a first drive axle operable to control vertical movement of a bottom part of the window shade, a second drive axle operable to adjust an inclination of multiple slats of the window shade, a sleeve affixed with the first drive axle, a transmission part connected with the second drive axle, an arrester assembled around the sleeve that has a locking state in which the arrester blocks a rotational displacement of the sleeve and the first drive axle to keep the bottom part at a desired position and an unlocking state in which rotation of the sleeve and the first drive axle is allowed, and a release unit connected with the arrester, characterized in that: the release unit includes an actuator, the actuator being operatively connected with the arrester and including a stick portion and an end connector assembly assembled with the outer casing, the stick portion having an elongated shape extending substantially vertical that defines a lengthwise axis, the end connector assembly allowing the stick portion to rotate about the lengthwise axis and move up and down relative to the outer casing, the end connector assembly including a joint part connected with the stick portion; wherein the actuator is operable to move downward from a first position to a second position to turn the arrester from the locking state to the unlocking state so that the bottom part is allowed to lower by gravity action, the joint part being coupled with the transmission part and rotatable with the stick portion to drive the second drive axle in rotation while the actuator is in the first position, and the joint part being displaced away from the transmission part by a downward displacement of the stick portion when the actuator is switched from the first position to the second position. an outer casing, a first drive axle operable to control vertical movement of a bottom part of the window shade, a second drive axle operable to adjust an inclination of multiple slats of the window shade, a sleeve affixed with the first drive axle, a transmission part connected with the second drive axle, an arrester assembled around the sleeve that has a locking state in which the arrester blocks a rotational displacement of the sleeve and the first drive axle to keep the bottom part at a desired position and an unlocking state in which rotation of the sleeve and the first drive axle is allowed, and a release unit connected with the arrester, characterized in that: the release unit includes an actuator, the actuator being operatively connected with the arrester and including a stick portion and an end connector assembly assembled with the outer casing, the stick portion having an elongated shape extending substantially vertical that defines a lengthwise axis, the end connector assembly allowing the stick portion to rotate about the lengthwise axis and move up and down relative to the outer casing, the end connector assembly including a joint part connected with the stick portion; wherein the actuator is operable to move downward from a first position to a second position to turn the arrester from the locking state to the unlocking state so that the bottom part is allowed to lower by gravity action, the joint part being coupled with the transmission part and rotatable with the stick portion to drive the second drive axle in rotation while the actuator is in the first position, and the joint part being displaced away from the transmission part by a downward displacement of the stick portion when the actuator is switched from the first position to the second position. the release unit includes an actuator, the actuator being operatively connected with the arrester and including a stick portion and an end connector assembly assembled with the outer casing, the stick portion having an elongated shape extending substantially vertical that defines a lengthwise axis, the end connector assembly allowing the stick portion to rotate about the lengthwise axis and move up and down relative to the outer casing, the end connector assembly including a joint part connected with the stick portion; wherein the actuator is operable to move downward from a first position to a second position to turn the arrester from the locking state to the unlocking state so that the bottom part is allowed to lower by gravity action, the joint part being coupled with the transmission part and rotatable with the stick portion to drive the second drive axle in rotation while the actuator is in the first position, and the joint part being displaced away from the transmission part by a downward displacement of the stick portion when the actuator is switched from the first position to the second position.