In today’s world where international academic communication and cooperation become frequent, publishing original research has become an embodiment of a university’s capacity, or even a nation’s capacity for scientific research and an embodiment of a country’s international influence. It is also an important parameter for assessing the academic performance of postgraduates. Enhancing students’ academic writing ability in English is essential not only in promoting international academic communication, but also in increasing the chance of making Chinese scholars heard in the international academic arena. English academic writing courses for postgraduates should be based on students’ needs, combining language study with students’ needs for academic research in their subject areas, thus enhancing their motivation and interest. Through pedagogical examples of teaching academic writing to postgraduate students majoring in architecture science, this paper discusses task design principles of English academic writing projects from the aspects of “purposefulness”, “specialism”, “critical thinking”, and “collaboration”. Among the four principles, “purposefulness” focuses on the three principal elements of academic writing ability, namely academic language, academic skills, and academic conventions. “Specialism” refers to the combination of the common core knowledge in language and the special linguistic characteristics of subject-specific discourse. This means teachers should deliberately guide and encourage students to integrate subject-specific knowledge into language learning consciously, transferring the common knowledge taught by teachers to the process of reading and writing subject-specific academic papers. “Critical thinking” concerns the ability to think critically in the process of English academic writing, such as the ability to analyze, infer, appraise, explain and interpret. “Collaboration” emphasizes learners’ ability to create a harmonious learning atmosphere through negotiation, communication and cooperation, so as to overcome the fear of difficulties and enhance self-confidence in order to improve the quality of language output. The principles mentioned above can not only have referential value for project-based English academic writing courses for postgraduates, thus enhancing students’ academic writing ability and realizing the goal of putting what they have learned into practice in the real world, but also bring some enlightenment of the undergraduate pre-course development of English academic writing.