If looking in the dianying's database it seems to be the right Wang Gang on the internets images (dunno how bulletproof this speculation is though), they list three Wang Gang's but only the one starring in Men Behind the Sun is credited as actor in TV-series.
This wasn't very easy, when comes to labaratory I have only seen his name being mention in the cast at DVDshopping-places but not noticed it in the various databases I looked in. I link these two more images of "wang gang's" from CnMDb if they could be useful to this investigation:
I've gotta think these are the same people. The very distinct earlobes and the additional fact that he uses glasses in his roles really makes me believe this is indeed him. Anyone else want to give their opinion?
I think the reason his looks different is that he gained some weight between the 90s and now (I believe these new pics are from his TV series)
Now also tagged Zhao Yongdong and Zheng Yongming, and will merge him as well: id 29383 演員 (1 電影) 黑太陽731 (1988) ... 眼鏡 副導演 (1 電影) 黑太陽731 (1988) 剪接 (1 電影) 黑太陽731 (1988)