The present disclosure provides a battery pack and an electric vehicle. The battery pack includes a sealed housing, and at least one housing structural beam and multiple electrode core strings electrically connected to one another located in the housing. The housing includes a housing body, including a top plate and a bottom plate arranged opposite to each other in a first direction. The structural beam is located between the top plate and the bottom plate, the at least one structural beam divides the interior of the housing into multiple accommodating cavities, the at least one structural beam is connected to the top plate and the bottom plate, and at least one electrode core string is provided in at least one accommodating cavity An atmospheric pressure in the accommodating cavity is lower than an atmospheric pressure outside the housing. A mounting portion is provided on the housing, and the mounting portion is configured to be connected and fixed to an external load. The electrode core string includes multiple electrode core assemblies sequentially disposed in a second direction and connected in series. The electrode core assembly is encapsulated in an encapsulation film. A length direction of the electrode core string extends in the second direction