The Grothendieck construction of a diagram X of categories can be seen as a process to construct a single category Gr(X) by gluing categories in the diagram together. Here we formulate diagrams of categories as colax functors from a small category I to the 2-category k-Cat of small k-categories for a fixed commutative ring k. In our previous paper we defined derived equivalences of those colax functors. Roughly speaking two colax functors X, X ′ : I → k-Cat are derived equivalent if there is a derived equivalence from X(i) to X ′ (i) for all objects i in I satisfying some "Iequivariance" conditions. In this paper we glue the derived equivalences between X(i) and X ′ (i) together to obtain a derived equivalence between Grothendieck constructions Gr(X) and Gr(X ′ ), which shows that if colax functors are derived equivalent, then so are their Grothendieck constructions. This generalizes and well formulates the fact that if two k-categories with a G-action for a group G are "G-equivariantly" derived equivalent, then their orbit categories are derived equivalent. As an easy application we see by a unified proof that if two k-algebras A and A ′ are derived equivalent, then so are the path categories AQ and A ′ Q for any quiver Q; so are the incidence categories AS and A ′ S for any poset S; and so are the monoid algebras AG and A ′ G for any monoid G. Also we will give examples of gluing of many smaller derived equivalences together to have a larger derived equivalence.