We propose an improvement method of coding efficiency of 8K UHDTV broadcasting by using HEVC/H.265. In recent years, 4K UHDTV broadcasting has been started in each country, which is broadcast at a bit rate of about 25-35 Mbps. In addition, 8K UHDTV test broadcasting started in Japan at a bit rate of about 85 Mbps. If 8K UHDTV can be broadcasted using a similar bit rate to 4K, it is useful for future 8K terrestrial broadcasting in Japan by 6 MHz per 1 channel (about 30 Mbps). In this study, we therefore consider how to broadcast 8K UHDTV using a similar bit rate to 4K UHDTV broadcasting. The proposed method uses low-pass filtering for 8K UHDTV video before HEVC/H.265 encoding to prevent coding degradation due to a low bit rate. This low-pass filtered video is then restored by a super-resolution method after HEVC/H.265 decoding. The super-resolution method uses image registration by using wavelet multi-scale bands in consideration of cutoff frequency of low-pass filtering. In addition, this super-resolution method has high image quality to utilize high self-similarity of an 8K UHDTV video frame, and it can use hardware implementation to perform real-time processing. Experiments show that the proposed method provides better PSNR measurements than the conventional HEVC/H.265 8K coder.