The present invention discloses a multi-layer Printed Circuit Board (PCB) and method for coupling block type multichannel optical signals, the method including the steps of i) forming one or more first optical via holes to allow one or more first optical signal coupling blocks to be inserted therein, ii) aligning a first optical waveguide and the first optical signal coupling blocks so that the first optical waveguide is interconnected to the first optical signal coupling blocks via an optical signal, iii) attaching a first fixing guide to a base board to fasten the first optical signal coupling blocks, iv) removing the first fixing guide and forming one or more second optical via holes to allow one or more second optical signal coupling blocks to be inserted therein, and v) repeatedly performing steps i) to iv) as many times as a number of layers of the multi-layer PCB.