As an emerging industry, space tourism has less relevant academic research than other traditional industries. In addition, space tourism is considered an industry with a high probability of civilianization (Toivonen, 2021). There is a line in Liu Yuxi’s composition “Wu Yi Xiang”: The swallows that once lived under the eaves of nobles have now flown into the homes of ordinary people. In the future, space tourism may no longer be the exclusive right of millionaires but a way for the general public to participate in travel. Therefore, predicting demand before the industry is fully mature is necessary to provide a roadmap for future practitioners to rely on and establish a unique perspective on future demand theoretical models in the current generation. Nonlinear prediction methods are an essential extension of linear-based methods with a higher potential to approach realistic and practical behaviors. Therefore, This study summarizes the application of nonlinear demand in the historical academic literature. It also outlines them and identifies the gaps with research implications. It is expected to assist future researchers in better modeling. At the same time, according to the existing literature, relevant future research inspiration has been proposed.