The pyrolysis characteristics of oil sludge and coal mixed fuel in an argon atmosphere were studied by thermogravimetric analyzer. Factors that affect the pyrolysis process were analyzed. The pyrolysis mechanism equation of the oil sludge and coal fuel was determined. Hereafter, the dynamic properties were provided, namely the activation energy and frequency factor. In this paper, pyrolysis of the mixture occurs in six distinct steps, each accompanied by its unique reactionary mechanics. The activation energy at each step increased with respect to temperature (presenting an initial increase and subsequent decrease). as the rate of temperature increase was amplified, each respective step has its activation energy slightly reduced. Moreover, the mixture shows the influence of non-linear relationships during pyrolysis.