1. A reaction method with a homogeneous-phase supercritical fluid, comprising:introducing a first fluid into a mixing chamber containing a molecular sieve component, wherein a mass of the first fluid into the mixing chamber is less than or equal to that can be absorbed by the molecular sieve component, totally absorbing the first fluid by the molecular sieve component;
introducing a second fluid into the mixing chamber, wherein a mass of the second fluid into the mixing chamber is greater than that can be absorbed by the molecular sieve component;
adjusting a temperature and a pressure in the mixing chamber to a critical temperature and a critical pressure of the second fluid, respectively, releasing the first fluid in supercritical phase from the molecular sieve component into the mixing chamber, followed by homogeneously mixing with the second fluid in supercritical phase in the mixing chamber to obtain a homogeneous-phase mixing fluid; and
introducing the homogeneous-phase mixing fluid into a reaction chamber connected to the mixing chamber for conducting a reaction.