A compact trigger source with low output jitter is designed based on Marx-circuit. The volume of the system is reduced to 0.20 m3 by integration of the charging power supply and triggering power supply, as well as the introduction of a four-terminal film capacitor with high energy density. The annular orbit-shaped electrode and the planar-triggering designs are employed to lower the output jitter and improve working stability of the field distortion spark-gap switch. The impulse voltage and working frequency can be adjusted in the range of 10-90 kV and 1-30 Hz, respectively. The maximum deviation of the output jitter is as low as 13.0 ns when the system runs 300 times at 30 Hz, which means there is only a 38% of growth for the output jitter when the working time increases by nine times. The trigger source is an ideal high-voltage trigger system, which shows low output jitter and high reliability.