syms l1 l2 l3 l11 l22 l33 a b Xp Yp Zp;[Xp,Yp,Zp]=solve('Zp-sqrt(l11^2-(Yp+a-b/2)^2)=l1','Zp-sqrt(l22^2-((2*a-b)/2-(Yp+sqrt(3)*Xp)/2)^2)=l2','Zp-sqrt(l33^2-((2*a-b)/2-(sqrt(3)*Xp-Yp)/2)^2)=l3','Xp','Yp','Zp')这样解试试