Timing control system is the important element for Magnetic Flux Compression Generator (MFCG)'s operation. This paper introduced the operating principle of classical timing control system using flat switch along with an analysis of its merits and drawbacks. Then it improved the classical timing control system by means of theoretic and experimental study, and designed a kind of timing control system, which used primacord and solidified coaxial switch. Furthermore, the explosive velocity of primacord and opening time of solidified switch were measured. Finally, the system in the experiment of MFCG was verified.