In this paper, we study the fourth-order m-point boundary value problem \begin{equation*} \left \{\begin{array}{lcr} u^{(4)}(t)=f(t,u(t)),\ t\in [0,1],\\ u’(0)=u’‘(0)=u(1)=0 , u’‘(1)-\sum^{m-2}_{i=1}\alpha_i u”’(\xi_i)=0, \end{array}\right. \end{equation*} with sign-changing Green’s function. By using some fixed theorems and the properties of Green’s function, we mainly establish the existence and multiplicity of positive solution for the problems under some suitable conditions.