This application relates to a motor controller and a powertrain. The motor controller includes a liquid cooling heat sink and an integrated component which includes an integrated housing and a capacitor core, and the integrated housing is configured to accommodate the capacitor core. The integrated housing includes two coolant through holes, and the two coolant through holes are separately configured to connect to the liquid cooling heat sink. In a first direction, the liquid cooling heat sink and the integrated housing are arranged in a stacked manner, and each coolant through hole runs through the integrated housing. In a second direction, a spacing between the two coolant through holes is less than a length of the liquid cooling heat sink. In a third direction, a diameter of each coolant through hole is less than a width of the liquid cooling heat sink. The motor controller has a compact layout.