Provided is a nanofiber based composite false twist yarn that is obtained by producing a nanofiber tape yarn by precisely slitting a nanofiber membrane produced by electrospinning and then twisting a nanofiber-only twist yarn that is obtained by twisting the nanofiber tape yarn or composite-twisting a nanofiber-only twist yarn and a natural fiber or synthetic fiber. The nanofiber based composite false twist yarn includes: a nanofiber tape yarn including at least one bonding portion or a false twist yarn which is obtained by false twisting the nanofiber tape yarn; and a natural fiber yarn or a synthetic fiber yarn that is composite-false-twisted with the nanofiber tape yarn or the false twist yarn, wherein the nanofiber tape yarn is made of a nanofiber web that is obtained by integrating polymer nanofibers made of a fiber-forming polymer material and having an average diameter of less than 1 μm thereby having fine pores.