In this paper, we investigate the outage performance of the intelligent reflecting surface (IRS)-assisted mobile edge computing (MEC) network, with a single user, a single computational access point (CAP), and a single IRS of N units, where the direct user-CAP link has been disabled. Based on the IRS-assisted MEC networks, we first define the outage probability (OutP) and propose two different IRS unit selection criteria to improve the outage performance. Moreover, according to the two IRS selection criteria, we derive the corresponding exact analytical expression and asymptotic expression, respectively, to analyze the outage performance and obtain some insights on the MEC network. In further, we adjust the deployment of the IRS location to optimize the system outage performance. Finally, simulation results show the effectiveness of the analysis and demonstrate the proposed optimization method of the IRS location. (C) 2022 Elsevier B.V. All rights reserved.