Nowadays, in Massive MIMO Relay Networks (MM-RNs), delay jitter decrease the video quality of users when they enjoy the Instant Video Communication (IVC) service. Cache is a promising technology to deal with the problem. In this paper, we study a high video quality guarantee problem. To mitigate the jitter, caching is applied to adjust the rate of transmitting side to adapt the rate of receiving side. The objective of this problem is to guarantee high video quality for IVC users. We derive a novel expressions for video quality with fairness in consideration. We also deduce the expression of delay and obtain a limit for the video frame queuing in cache. Since the problem is convex, we solve it by employing the convex optimization methods. Based on bisection searching, a Video Quality Guarantee (VQG) algorithm is designed to achieve the methods. Various simulations are shown to demonstrate the effectiveness of our proposed algorithm.