The invention provides a thermal plasma array reactor for producing acetylene by pyrolysis of coal. The reactor comprises a pre-dispersion section for coal dust, a plasma array reaction section, and a quenching section; multiple rows of plasma electrodes are arranged on one side wall surface of the plasma array reaction section, each row of electrodes comprise multiple electrodes, adjacent two rows of electrodes are arranged parallelly or alternately, arc discharge is generated between electrode pairs, and an array shaped arc plasma field is formed; gas carries coal dust and passes the pre-dispersion section for coal dust, uniformly distributed coal dust passes the array shaped arc plasma field formed by the electrodes from up to bottom, coal dust is rapidly heated and instantly reaches thermodynamic balance at a high temperature environment, pyrolysis gas rich in acetylene is formed, a mixed material passes a plasma zone and enters subsequent reactions and a separating unit, in order to obtain an acetylene product. The reactor has the characteristics of high pyrolysis efficiency of coal dust, high utilization efficiency of energy, high acetylene content in the product, long time steady running, and the like.