本文对一次烧成工艺和二次烧成法制成的n-型SrTiO_3半导瓷的非线性V-Ⅰ关系作了定性描述。着重讨论了V-Ⅰ特性曲线3个区的导电机理。根据烧成工艺,建立了改进的双层晶界势垒模型。在此基础上,对n-型SrTiO_3半导瓷非线性V-Ⅰ特性曲线上3个特征区的电压电流关系作了定量推导和计算。对计算结果与实验结论作了比较,给出不超过3％的最大误差。 In this paper, the relationship between the non-linear V-Ⅰ of the n-type SrTiO_3 semiconducting porcelain made by one firing process and the secondary firing method was qualitatively described. The conduction mechanism of three regions of V-Ⅰ characteristic curve is emphatically discussed. According to the sintering process, an improved double-layer grain boundary barrier model is established. On this basis, the voltage and current relations of three characteristic regions on the nonlinear V-Ⅰ characteristic curve of n-type SrTiO_3 semiconducting porcelain were quantitatively deduced and calculated. The calculation results and experimental conclusions were compared, giving a maximum error of not more than 3%.