The invention discloses an ion source filament used for an ion implanter and a clamping device for the ion source filament. An ion source used for the ion implanter can produce wide belts or flat belts, the filament and the clamping device for the filament allow for normal operation of the ion source, and accordingly stable strong electrons are produced. The clamping device for the filament mainly comprises the filament (1), a filament connecting rod (2), a graphite support plate (3), an insulated ceramic seat (4), a filament clamp (5), a power input belt (6) and the like. The clamping device for the filament is characterized in that the special filament (1) is disposed on the filament connecting rod (2), and the special filament clamp (5) is connected with the filament connecting rod (2) and the power input belt (6); and the filament (1) can emit high-strength electrons, and the filament clamp (5) can firmly fix the filament connecting rod (2) and transmit high voltage. Detailed explanation of operation principle of the clamping device for the filament is shown and a specific implementation scheme is given in an instruction book.