为了提高非链式脉冲DF激光器注入能量和放电稳定性，研究了火花针紫外预电离放电引发非链式脉冲DF激光器的电路特性。通过分析工作气体中SF6分子的碰撞解离及其对电子的吸附过程，得到了电子连续性方程，结合放电回路基尔霍夫方程建立了描述DF激光器放电特性的数学模型。运用该模型模拟了预电离放电电压、主放电电压及电流随时间的变化关系，模拟结果较真实地反映了预电离放电与主放电之间的时间延迟、主电极间的击穿及自持放电等物理过程。利用非链式脉冲DF激光器样机对模拟结果进行了相应的实验验证，测量得到的主、预放电电压波形与修正后的模拟电压波形一致。进而运用该模型研究了主储能电容、延迟电感、锐化电容对放电特性的影响，得到了有助于提高DF激光器放电性能的电路参数。

The circuit parameters of spark pin ultroviolet (UV) pre-ionization discharge non-chain pulsed DF laser is researched to improve its discharge uniformity and electric energy depositions. Through analysis the process of dissociation of SF6 molecules and the attachment of electrons to SF6 molecules, the continuity-equations for electrons is obtained. Combination with the Kirchhoff equations for discharge circuit, the mathematical model is established to describe the discharge parameters of DF laser. Based on this model, the voltage waveforms of pre-ionization and main discharge, also the current waveform of main discharge are solved numerically. The results display some physical processes correctly, such as the delay time between pre-ionization and main discharge, breakdown of the main electrode and the self-maintained discharge. Then the corresponding experiments are carried out to verify the results of this model. The measured pre-ionization and main discharge voltage waveforms are consistent with the simulation results. Using this model, the influences of main store capacitance, delay inductance, peak capacitance on the discharge are researched individually, and the circuit parameters of DF laser are obtained that is useful to improve the discharge stability.