\[Rho] = 0.9, \[Beta] = 2, \[Gamma] = 1, \[Alpha] = 1, Subscript[\
\[Epsilon], c] = 2, Subscript[\[Delta], c] = 3, Subscript[\[Delta], \
p] = 2, Subscript[\[Mu], c] = 15, Subscript[\[Mu], p] = 12, \
Subscript[q, 0] = 0
Plot[V[q] = -Subscript[\[Delta], c]/(\[Rho] - \[Beta]) q + (1/\[Rho])[
Subscript[\[Epsilon], c] +
1/((\[Rho] - \[Beta]) (\[Rho] - \[Beta])) ((\[Gamma]*\[Gamma]*
Subscript[\[Delta], c]*Subscript[\[Delta], p])/
Subscript[\[Mu],
p] + (\[Alpha]*\[Alpha]*Subscript[\[Delta], c]*
Subscript[\[Delta], c])/(2 Subscript[\[Mu], c]))], {q, 0,
10}]
第一行为参数的值，第二行就是函数、自变量了，不知道哪里有问题。谢谢，麻烦大家了。

具体是这个样子

\[Rho] = 0.9; \[Beta] = 2; \[Gamma] = 1; \[Alpha] = 1; \[Epsilon]c = \
2; \[Delta]c = 3; \[Delta]p = 2; \[Mu]c = 15; \[Mu]p = 12; q0 = 0;
V[q_] := -\[Delta]c/(\[Rho] - \[Beta]) q + (1/\[Rho]) \[Epsilon]c +
1/((\[Rho] - \[Beta]) (\[Rho] - \[Beta])) ((\[Gamma]*\[Gamma]*\
\[Delta]c*\[Delta]p)/\[Mu]p + \
(\[Alpha]*\[Alpha]*\[Delta]c*\[Delta]c)/(2 \[Mu]c))
Plot[V[q], {q, 0, 10}]