A capacitor and power device assembly having a cooling structure, wherein the capacitor and power device assembly comprises an upper cover plate , a casing , a lower cover plate , a capacitor and power devices, the capacitor is disposed in a cavity of the casing , and the power devices are respectively disposed on outer sides of the upper cover plate and the lower cover plate ; the cooling structure comprises a first liquid inlet and a first liquid outlet that are disposed on the upper cover plate and/or the lower cover plate ; and the cooling structure further comprises a first cooling passage and a second cooling passage that are respectively disposed on upper and lower sides of each of the upper cover plate and the lower cover plate , the first cooling passage is configured to cool the capacitor, and the second cooling passage is configured to cool the power devices; the first cooling passage is respectively disposed between an upper bottom plate of the casing and the upper cover plate and between or a lower bottom plate of the casing and the lower cover plate ; and the first cooling passage comprises separation ridges disposed at a middle position of the first cooling passage and extending in a length direction of the casing , and the separation ridges divide the first cooling passage into a first liquid inlet cooling passage and a first liquid outlet cooling passage ; the second cooling passage comprises a number of coolant tanks disposed on outer surfaces of the upper cover plate and the lower cover plate and at positions corresponding to positions of the power devices; and a bottom of the coolant tank is provided with a second liquid inlet communicated with the first liquid inlet cooling passage and a second liquid outlet communicated with the first liquid outlet cooling passage . the cooling structure comprises a first liquid inlet and a first liquid outlet that are disposed on the upper cover plate and/or the lower cover plate ; and the cooling structure further comprises a first cooling passage and a second cooling passage that are respectively disposed on upper and lower sides of each of the upper cover plate and the lower cover plate , the first cooling passage is configured to cool the capacitor, and the second cooling passage is configured to cool the power devices; the first cooling passage is respectively disposed between an upper bottom plate of the casing and the upper cover plate and between or a lower bottom plate of the casing and the lower cover plate ; and the first cooling passage comprises separation ridges disposed at a middle position of the first cooling passage and extending in a length direction of the casing , and the separation ridges divide the first cooling passage into a first liquid inlet cooling passage and a first liquid outlet cooling passage ; the second cooling passage comprises a number of coolant tanks disposed on outer surfaces of the upper cover plate and the lower cover plate and at positions corresponding to positions of the power devices; and a bottom of the coolant tank is provided with a second liquid inlet communicated with the first liquid inlet cooling passage and a second liquid outlet communicated with the first liquid outlet cooling passage . <EOS>