The invention relates to the technical field of electric vehicle parts, particularly an electric vehicle controller heat dissipation device fixed by an elastic sheet. A heat dissipation seat of the heat dissipation device is provided with a long strip-shaped elastic sheet; a fixed edge of the long strip-shaped elastic sheet is fixed on the upper top surface of a hollow cavity through a connecting piece; the long strip-shaped elastic sheet is provided with a downward elastically pressing edge; the elastically pressing edge elastically abuts against power switch tubes arranged in rows at the inner side of the fixed edge, and therefore, the power switch tubes can abut against a mounting plane of the hollow cavity, and aluminum strips are not required to be mounted, and the power switch tubes are not required to be mounted one by one.; and thus, the electric vehicle controller heat dissipation device fixed by the elastic sheet is advantageous in convenient installation, simplification of production process and reduction of production cost; bolts are not required to pass through the power switch tubes, and therefore, the problem of incapability of fully satisfying a requirement of high-voltage resistant insulation resistance caused by close creepage distance between the bolts and the power switch tubes of a heat dissipation seat of a traditional heat dissipation device can be avoided; and the heat dissipation path of the heat dissipation seat is shorter than that of the traditional heat dissipation seat, such that, heat energy can be dissipated faster, and therefore, overheating damage rate of the heat dissipation seat is greatly reduced, and the service life of the heat dissipation seat can be prolonged.