通过进行工艺参数(激光功率、扫描速度和送粉速率)可控的单道激光熔覆实验，观察了沉积轨迹横截面形貌的变化；提出了单一参数（δ参数，δ=wtan β/2h）控制的横截面形貌曲线方程。根据横截面几何特征参数：沉积轨迹宽度w、高度h、面积F和沉积角β的测量数据，用回归处理方法，给出了δ参数与横截面名义面积Fm（Fm=wh）之间的函数关系，得到了横截面形貌随Fm的变化规律；同时用F和β的测量数据验证了横截面形貌曲线方程。

The tracks cross-section morphological variaiton of single laser with the controllable processing parameters, such as laser power, scanning speed, and powder mass flow rate, is observed by means of the single laser cladding experiment. A curvilinear equation describing cross-section morphology controlled by a single parameter (δ=wtan β/2h) is proposed. According to the measurement datas of cross-section geometrical characteristic parameters: width w, height h, area F and deposition angle β, the functional relationship between the parameter δ and the nominal area Fm (Fm=wh) of the cross-section is established by applying the regression processing method. And the regularity of cross-section morphology is determined with the variation of Fm. The curvilinear equation of cross-section morphology is testified by the measurement datas of F and β.