With the continuous development of digital technology and the Internet of Things (IoT), the teaching methods for architecture major in higher vocational colleges have also undergone major changes. New technologies and instruction methods in Engineering Cost Budgeting teaching can stimulate students’ learning interest and improve education quality and students’ comprehensive learning ability. In order to improve the teaching level of engineering cost budgeting major and stimulate students’ interest in learning, this work first introduces backpropagation neural network (BPNN) into engineering cost estimation (ECE). Then, the BPNN-based ECE model is trained by the sample data to estimate the project’s total quotation and comprehensive unit price. The error between the real and predicted values is analyzed. Second, the building information modeling (BIM) technology and virtual reality (VR) technologies are integrated into teaching engineering cost budgeting. The investigation, research, and analysis are conducted before and after applying BIM and VR technology in practical teaching. The results show that the proposed BPNN-based ECE model-estimated total quotation and comprehensive unit price fit well the sample values. The BPNN-based ECE model can be applied to teaching engineering cost budgeting. It can improve the calculation accuracy, and the relative error can be controlled within a certain range and has a certain potential to replace manual budgeting. It can provide some reference for the research of engineering cost technology. Classroom teaching under the integration of BIM and VR technologies can improve the students’ homework quality, academic performance, and teaching quality to a certain extent. Integrating BIM and VR technology in classroom teaching can enhance students’ communication, cooperation ability, oral defense scores, comprehensive scores, and professional skills.