Reflecting on the evolution of standards for induction heating bent pipe development, this paper introduced the key aspects of these standards and interprets the symbols in the formula for the wall thickness reduction rate C on the outer arc side of induction heating bent pipes. By analyzing the variation trend of wall thickness and stress before and after pipe bending process for both induction heating bent pipes and steel plate heating pressed welded bent pipes, this paper showed the discrepancies on wall thickness calculation for heating bent pipe in current standards. This paper also provided concepts for variable and constant wall thickness bent pipe, along with their calculation methods for stress distribution and wall thickness. It substantiates these points with cases from ASME B31.3-2010 Process piping regarding bent pipe wall thickness calculation formula and the location of initiation cracks from hydraulic burst test on induction heating bent pipes. On this basis, this paper suggests revising the bent pipe wall thickness calculation formulae in relevant standards. This paper provides concept and structure for dual wall thickness bent pipe based on the hazardous location under stress distribution and strength condition.