An extraction cassette for extracting nucleic acid from a mixed liquid including a sample, comprising: a liquid receiving module for receiving the sample and alcohol and for mixing the sample with the alcohol to generate the mixed liquid; and an extraction module for capturing the nucleic acid from the mixed liquid; wherein the liquid receiving module communicates with the extraction module, and the liquid receiving module comprises a receiving module body having a first side, a second side opposite to the first side and a sample feeding hole formed on the first side; wherein the receiving module body comprises: a sample compartment formed on the receiving module body and configured to receive the sample, wherein the sample compartment communicates with the sample feeding hole, and an alcohol compartment, formed on the receiving module body and configured to receive the alcohol, wherein the alcohol compartment communicates with the first sample compartment via a first path; characterized in that the liquid receiving module further comprises a sealing member adapted to seal the sample feeding hole, wherein the sample compartment comprises a first sample compartment connection hole and a second sample compartment connection hole for connecting to the extraction module, the first sample compartment connection hole nears the first side relative to the second side, the alcohol compartment comprises an alcohol compartment connection hole that nears the second side relative to the first side, the first path connects the alcohol compartment connection hole to the first sample compartment connection hole for transferring the alcohol from the alcohol compartment to the sample compartment, and at least one portion of the first path is located between the alcohol compartment and the second side. a liquid receiving module for receiving the sample and alcohol and for mixing the sample with the alcohol to generate the mixed liquid; and an extraction module for capturing the nucleic acid from the mixed liquid; wherein the liquid receiving module communicates with the extraction module, and the liquid receiving module comprises a receiving module body having a first side, a second side opposite to the first side and a sample feeding hole formed on the first side; wherein the receiving module body comprises: a sample compartment formed on the receiving module body and configured to receive the sample, wherein the sample compartment communicates with the sample feeding hole, and an alcohol compartment, formed on the receiving module body and configured to receive the alcohol, wherein a sample compartment formed on the receiving module body and configured to receive the sample, wherein the sample compartment communicates with the sample feeding hole, and an alcohol compartment, formed on the receiving module body and configured to receive the alcohol, wherein the alcohol compartment communicates with the first sample compartment via a first path; characterized in that the liquid receiving module further comprises a sealing member adapted to seal the sample feeding hole, wherein the sample compartment comprises a first sample compartment connection hole and a second sample compartment connection hole for connecting to the extraction module, the first sample compartment connection hole nears the first side relative to the second side, the alcohol compartment comprises an alcohol compartment connection hole that nears the second side relative to the first side, the first path connects the alcohol compartment connection hole to the first sample compartment connection hole for transferring the alcohol from the alcohol compartment to the sample compartment, and at least one portion of the first path is located between the alcohol compartment and the second side.