The invention discloses a method for co-production of synthesis gas preparation by chemical chain reforming of carbon-containing fuel and power generation by SOFC (solid oxide fuel cell). The method comprises steps as follows: (1), synthesis gas with CO and H2 as main components is obtained through reaction between the carbon-containing fuel and an oxygen carrier in a chemical chain reforming reactor; (2), the oxygen carrier after the reaction is contacted with a positive pole of an SOFC, electrons are released to a negative pole of the SOFC through an external circuit, and current is formed; (3), the synthesis gas preparation adopting chemical chain reforming and an electrochemical reaction process are performed alternately, and co-production of the synthesis gas preparation by chemical chain reforming of carbon-containing fuel and the power generation by the SOFC is realized. According to the method, the problem that the positive pole of SOFC carbon-based fuel is prone to carbon deposition is solved, applicability to the carbon-based fuel is expanded, energy utilization efficiency of a system is improved, meanwhile, multiple problems produced through direct contact between the electrodes of the high-temperature SOFC and the carbon-based fuel are solved indirectly, and implementation difficulty and cost of an internal reforming technology are reduced.