Technology has been increasingly used to promote students' engagement in online learning environments. Engagement refers to the students' commitment or effort involved in learning. Engagement often has various categories such as behavioral, emotional, and cognitive engagement. In this paper, a technology-supported learning model is proposed for the purpose of promoting students' engagement in online learning. This model is composed of three key components: pedagogical design, social design, and technical design. Pedagogical design aims to achieve predefined learning objectives through well-designed instructional strategies and learning activities so that students can be behaviorally engaged (e.g., high participation, active exploration) and cognitively engaged (e.g., asking questions, giving evaluative comments). Social design is to create a comfortable and friendly setting where students are willing to interact with peers and/or with the teacher so that emotional engagement (e.g., positive social relationship between students and the teacher) and cognitive engagement (e.g., knowledge construction) can be attained. Technical design intends to create a usable platform that students can easily manipulate without technical difficulties. All these designs must take the context (e.g., elementary education level) into careful consideration.