Abstract: Based on the development practice, a C-band multi-beam klystron transmitter for vehicle radar is introduced. The transmitter is characterized by wide pulse width, high output power, high maneuverability and high reliability. It can work stably for a long time under various environmental conditions of plain and plateau. The design scheme and system composition of the transmitter are described in this paper. By comparing with the previous transmitter design methods of the same power level, the improvements and implementation effects are given. The emphases are focused on the design methods from four aspects: wide-pulse design of all-solid-state modulator, design of high voltage power supply with high stability, miniaturized and lightweight structural design, plateau adaptive design.