The　paper　presents　a　degree　of　freedom　expanding　method　for　dealing　with　the　connections　of　3D　isoparametric　solid　elements　and　the　degenerated　shell　elements.　By　introducing　two　degrees　of　freedom　to　describe　the　elongation　in　the　normal　direction　of　the　shell　node　linked　with　solid　elements,　a　series　of　multipoint　constraint　equations　which　provide　proper　connections　of　solid　and　shell　nodes　are　raised.　The　method　gives　a　complete　solution　to　the　problem　of　connection　between　3D　isoparametric　solid　elements　and　degenerated　shell　elements　even　for　the　thermal　elasto-plastic　problem.　It　can　adapt　to　complex　junctions　and　simplify　programming.　Numerical　examples　are　also　presented　to　demonstrate　the　accuracy　and　feasibility　in　thermal　elasto-plastic　analysis.