本文提出了定基形矩阵的概念及多变量系统的行简化梯形典范形理论。该典范形与系统的可观测性矩阵或可控性矩阵之间可用子块集建立计算关系式。应用该理论可以把最小阶Kx-观测器设计中的一组非线性代数方程组化为一类可解的线性代数方程组(附录中介绍了这一分析过程)。由此得到一种新的最小阶Kx-观测器线性设计法。该算法较Roman-Bullock设计法计算简单,计算误差小,且更便于用计算机设计。文中还用例题指出Sirisena设计法的缺点。 This paper presents the concept of fixed basis matrices and the theory of simplified trapezoidal normal form for multivariable systems. The relation between the canonical form and the system’s observability matrix or controllability matrix can be established by using sub-block sets. Applying this theory, we can group a group of nonlinear algebraic equations in the minimal Kx-observer design into a class of solvable linear algebraic equations (this appendix describes this analysis process). Thus a new minimum order Kx-observer linear design method is obtained. Compared with the Roman-Bullock design method, this algorithm is simpler in calculation, less inaccuracy and easier to design with computer. The article also points out the shortcomings of the Sirisena design method.