The co-pyrolysis of wet sewage sludge and straw was studied in a fixed bed reactor. A series of wet sludge with different moisture content and straw were blended and pyrolyzed in the range of 600℃ to 900℃ to investigate the influence of reactor temperature, moisture content of wet sludge and straw content on the gas composition. When the moisture content of wet sludge was constant, the content of H2 and CO gradually increased as the reactor temperature increased. At the same temperature, the content of H2 showed a trend of increasing first and then decreasing as the moisture content of wet sludge increased. However, the content of CO showed a gradual decline. When the moisture content of wet sludge was 60%, the content of H2 reached a maximum. According to co-pyrolysis experiment results, the proper straw addition ratio was about 40wt%.