An electric assembly for a vehicle, comprising: a box assembly , wherein a mounting plate is disposed in the box assembly , the mounting plate divides a space within the box assembly into a motor holding cavity and a transmission holding cavity that are arranged along an axial direction of a motor shaft , and the mounting plate has a shaft via-hole making the motor holding cavity and the transmission holding cavity be in communication with each other; a motor , wherein the motor is disposed in the motor holding cavity ; and a transmission , wherein the transmission is disposed in the transmission holding cavity , and the motor is power-coupled to the transmission , wherein the box assembly comprises a transmission box and a motor box , the transmission box comprises a front box and a rear box , the motor box comprises a motor housing and a motor backend cover , the front box and the motor housing are disposed adjacent to each other, and the mounting plate is constructed as a part of the front box or a part of the motor housing , characterized in that the front box and the motor housing are integrally formed, and in that one or more of a first connection rib , a second connection rib and a third connection rib are connected between an outer surface of the front box and an outer surface of the motor housing , the first connection rib is connected between an upper end face of the motor housing and an upper end face of the front box , the second connection rib is connected between a lower end face of the motor housing and a lower end face of the front box , and the third connection rib is located between the first connection rib and the second connection rib . a box assembly , wherein a mounting plate is disposed in the box assembly , the mounting plate divides a space within the box assembly into a motor holding cavity and a transmission holding cavity that are arranged along an axial direction of a motor shaft , and the mounting plate has a shaft via-hole making the motor holding cavity and the transmission holding cavity be in communication with each other; a motor , wherein the motor is disposed in the motor holding cavity ; and a transmission , wherein the transmission is disposed in the transmission holding cavity , and the motor is power-coupled to the transmission , wherein the box assembly comprises a transmission box and a motor box , the transmission box comprises a front box and a rear box , the motor box comprises a motor housing and a motor backend cover , the front box and the motor housing are disposed adjacent to each other, and the mounting plate is constructed as a part of the front box or a part of the motor housing , characterized in that the front box and the motor housing are integrally formed, and in that one or more of a first connection rib , a second connection rib and a third connection rib are connected between an outer surface of the front box and an outer surface of the motor housing , the first connection rib is connected between an upper end face of the motor housing and an upper end face of the front box , the second connection rib is connected between a lower end face of the motor housing and a lower end face of the front box , and the third connection rib is located between the first connection rib and the second connection rib . <EOS>