The utility model relates to a double -deck cable trench cover device, including the translation device of upper strata apron, lower -layer cover board, lower -layer cover board, evenly interval system has a ventilation hole of a plurality of rectangular shapes on upper strata apron and lower -layer cover board, the interval and the size in ventilation hole make the lower -layer cover board make its sclausura locate just can shelter from the porose department of upper strata apron through the translation, or the lower -layer cover board makes the ventilation hole with the upper strata apron all expose through the translation. This device has been solved the cable and both can have been ventilated, again can dirt -proof problem, compensatied the shortcoming of prior art cement cover plate and mesh -shaped cover board simultaneously.