Due to the importance of the problem of testing the product units under stress higher than normal stress conditions, specially used in reliability analysis. In this paper, we discuss the problem of estimation with step stress partially accelerated life tests, the lifetime of testing items under use condition follow the inverted exponentiated Lomax distribution. The test is running under progressive Type-II censoring scheme, and the units drawn from the test were distributed as a binomial distribution. The model parameters and acceleration factor are estimated by maximum likelihood and Bayesian methods. The corresponding asymptotic confidence intervals as well as credible intervals are also constructed. The method for Bayesian estimates for the parameters of the IEL distribution under PTII censoring based on SS-PALT model is presented. Also, the theoretical results are assessed and compared through Monte Carlo simulation study. Two real data set are used to illustrate how the approaches will perform in practice. Finally, we reported some comments about numerical computation.