An electrolytic reactor of an oxyhydrogen machine includes a main body with an internal chamber for accommodating a liquid, a carrier installed to the chamber for arranging even numbered electrode plates which are spaced from each other and two adjacent electrode plates having different polarities, a multiple of partitions extending to an appropriate length from the top surface to the bottom surface of the main body and spaced from each other, a communicating channel formed by each electrode plate and the main body and disposed between the bottom surface of the main body and each electrode plate, a liquid storage portion formed by the space between the partitions and the chamber and communicated to the communicating channel and a gas extraction unit installed on the main body and having independent first and second gas collection chambers for collecting hydrogen and oxygen respectively.