加、乘常数是影响全站仪光电结构系统性偏差的重要因素，如何测定对部分测绘从业人员来说比较陌生。介绍目前国内最常用的六段比较法测定加、乘常数的原理、计算方法及精度影响因素，结合试验数据，对野外基线点的布设进行研究分析，论证了不同布设方案的测定精度及效率，并提出了新的野外基线点布设方案。

Addition constants and proportion constants are important factors that affect the systematic deviations of the photoelectric structures of total stations. Some mapping staffs, however, are unfamiliar with the determination of the addition constants and proportion constants. The principle, calculation method and accuracyaffecting factors of the sixrange method, which is often used in China to determine the addition constants and proportion constants, are presented in the paper. The layout of the field baseline points is analyzed and the survey accuracy and survey efficiency of different layout schemes are studied on basis of test data. Finally, new field baseline point layout schemes are proposed.