Introducing lattice strain at dissimilar interfaces has been considered as an efficient approach to enhance the ionic conductivity in thin electrolyte film of solid oxide fuel cells (SOFCs). However, quantitative analysis on depth profile of double strained crystal interfaces is still lacking. In this report, the ionic conductivity evolution of isotropic crystal with double strained interfaces is evaluated quantitatively. The correlation between ionic conductivity enhancement and intrinsic parameters of double strained electrolyte materials (layer sequence, Young's modulus, Poisson's ratio) is investigated. A prototype isotropic cubic lattice crystal (YSZ) is employed to verify our model. The results show that the synergetic effects of double lattice strain on ionic conductivity are more prominent than that of the single lattice strain. Our work provides insightful guidelines to enhance the ionic conductivity in electrolyte of SOFCs by introducing the double lattice strain at the nanoscale heterostructures. (C) 2017 Published by Elsevier B.V.