The invention relates to the technical field of methanol synthesis, in particular to a synthesis system and preparation equipment. The synthesis system comprises a first synthesis assembly and a second synthesis assembly, wherein the first synthesis assembly and the second synthesis assembly are communicated; the first synthesis assembly is used for communicating with an external synthesis gas storage device. According to the synthesis system provided by the invention, the first synthesis assembly and the second synthesis assembly are connected in a serial connection mode; unreacted synthesis gas in the first synthesis assembly is continuously introduced into the second synthesis assembly to take a reaction for synthesis; the unreacted does not need to be conveyed to the first synthesis assembly again after the pressurization through a circulation compressor. Therefore the synthesis system provided by the invention has the advantages that a circulation compressor with a complicated inside structure and great electricity consumption is omitted, so that the operation cost of the synthesis system is lower; the operation and the maintenance are simple.