Shiming has met the IBF flyweight three times before and won twice, but he is aware that the stakes are far higher than when the pair fought before as amateurs.
Shiming and Ruenroeng will face off at the Macao Venetian on 7 March, and Shiming told the South China Morning Post that he is not taking anything for granted.
He said: "I won't go into the ring thinking I am a superior fighter just because I won our last two fights. We are fighting as professionals and Amnat has a slight edge over me because he has been a professional a year longer than me. I expect a completely different fighter than the one I met in the ring five years ago.
"I have made the transition from amateur to professional boxing and I am ready for the fight. I have eliminated all the amateur stuff in my boxing and I am ready to challenge for the title."
He also spoke about his relief that trainer Freddie Roach recovered from back surgery in time to join his for the final leg of his training.
Shiming added: "Freddie will help me out as he has always done. In fact, he travelled with me to Shanghai [for promotional activities] and left yesterday so he should be good to go next month. Freddie has worked in my corner for all six of my professional fights. We will team up together for a seventh professional fight. This will be our biggest fight together. Nothing has changed."