An image capturing module, comprising: a casing; a camera unit disposed in the casing; a circuit board device connected to the camera unit and disposed in the casing, the circuit board device comprising: a circuit board unit disposed at a periphery of the camera unit and comprising a functional module; and a heat dissipation device comprising: a heat sink attached on a surface of the functional module for dissipating heat from the functional module. wherein the casing comprises a first housing body, a second housing body connected to the first housing body, a front enclosure, and a back enclosure, the first housing body, the second housing body, the front enclosure, and the back enclosure jointly enclosing a receiving space for receiving the camera unit, the circuit board device, and the heat dissipation device, wherein the casing further comprises a ventilating window in communication with the receiving space and for ventilating the receiving space, and wherein the ventilating window is formed at a positon on the casing close to the front enclosure, wherein the ventilating window comprises a first opening portion, characterized in that the ventilating window further comprises: a second opening portion connected to the first opening portion, the second opening portion being arranged farther away from the front enclosure than the first opening portion, and the second opening portion including an opening having an arcuate profile inclined relative to an optical axis of the camera unit and oriented towards the front enclosure. a casing; a camera unit disposed in the casing; a circuit board device connected to the camera unit and disposed in the casing, the circuit board device comprising: a circuit board unit disposed at a periphery of the camera unit and comprising a functional module; and a heat dissipation device comprising: a heat sink attached on a surface of the functional module for dissipating heat from the functional module. wherein the casing comprises a first housing body, a second housing body connected to the first housing body, a front enclosure, and a back enclosure, the first housing body, the second housing body, the front enclosure, and the back enclosure jointly enclosing a receiving space for receiving the camera unit, the circuit board device, and the heat dissipation device, wherein the casing further comprises a ventilating window in communication with the receiving space and for ventilating the receiving space, and wherein the ventilating window is formed at a positon on the casing close to the front enclosure, wherein the ventilating window comprises a first opening portion, characterized in that the ventilating window further comprises: a second opening portion connected to the first opening portion, the second opening portion being arranged farther away from the front enclosure than the first opening portion, and the second opening portion including an opening having an arcuate profile inclined relative to an optical axis of the camera unit and oriented towards the front enclosure. a circuit board unit disposed at a periphery of the camera unit and comprising a functional module; and a heat dissipation device comprising: a heat sink attached on a surface of the functional module for dissipating heat from the functional module. wherein the casing comprises a first housing body, a second housing body connected to the first housing body, a front enclosure, and a back enclosure, the first housing body, the second housing body, the front enclosure, and the back enclosure jointly enclosing a receiving space for receiving the camera unit, the circuit board device, and the heat dissipation device, wherein the casing further comprises a ventilating window in communication with the receiving space and for ventilating the receiving space, and wherein the ventilating window is formed at a positon on the casing close to the front enclosure, wherein the ventilating window comprises a first opening portion, characterized in that the ventilating window further comprises: a second opening portion connected to the first opening portion, the second opening portion being arranged farther away from the front enclosure than the first opening portion, and the second opening portion including an opening having an arcuate profile inclined relative to an optical axis of the camera unit and oriented towards the front enclosure. a heat sink attached on a surface of the functional module for dissipating heat from the functional module. wherein the casing comprises a first housing body, a second housing body connected to the first housing body, a front enclosure, and a back enclosure, the first housing body, the second housing body, the front enclosure, and the back enclosure jointly enclosing a receiving space for receiving the camera unit, the circuit board device, and the heat dissipation device, wherein the casing further comprises a ventilating window in communication with the receiving space and for ventilating the receiving space, and wherein the ventilating window is formed at a positon on the casing close to the front enclosure, wherein the ventilating window comprises a first opening portion, characterized in that the ventilating window further comprises: a second opening portion connected to the first opening portion, the second opening portion being arranged farther away from the front enclosure than the first opening portion, and the second opening portion including an opening having an arcuate profile inclined relative to an optical axis of the camera unit and oriented towards the front enclosure.