(1) Sequential examination: Except for special circumstances, the examiner shall examine the utility model patent application in sequence according to the filing date or the time when the patent application file is submitted to the examiner, so as not to make some defects more common Or the case files that are more difficult to examine have been in the hands of examiners for a long time, ensuring the smooth operation of the utility model patent examination process. (2) Principle of written review: During the review procedure, written documents should be used as the basis and the written documents should be included in the case file. Except for the obvious errors in words and symbols that do not involve rights, which are stipulated in Paragraph 4 of Article 51 of the Implementing Rules of the Patent Law, which can be corrected ex officio, the examiner shall notify the patent applicant to make any modifications to replacement pages. The original documents should be kept in the case file and should not be returned to the applicant. (3) Principle of proof: During the examination of utility model patent applications, when the examiner is preparing to reject a patent application, he should have sufficient legal basis and support his reasons with facts, and should not just give a categorical conclusion. (4) Hearing principle: During the examination procedure for a utility model patent application, the applicant has the right to explain his or her opinions, requirements and claims in a statement of opinion. (5) Principle of economical procedure: The examiner shall work in accordance with the examination procedures for utility model patent applications and shall conclude the case in the shortest possible procedure.