Cost and fabrication technique, as two important factors affecting the development and practical applications of electronic devices, have attracted extensive attention of researchers. In order to overcome the shortcomings of high-cost raw materials and complex fabrication process, in the present work, a low-cost (the cost of per strain sensor is less than one cent ($0.01)) and environment-friendly strain sensor based on common daily goods of carbon ink and elastic core-spun yarn is fabricated by a facile solution processing method. The results show that the as-fabricated strain sensor possesses acceptable sensitivity (a gauge factor of 6.1 under the strain range of 0.5–20%) and rapid response and recovery speed (response/recovery times under a strain of 10%: 110/80 ms). Moreover, the facile solution processing method and tailorable length of the elastic core-spun yarn allow it to be fabricated into strain sensors with different specifications for meeting the needs of various application situations. Based on its many advantages, the strain sensor is successfully used for monitoring multiple human motions. This facile approach can be used for developing low-cost strain sensors and also provides inspiration for developing new applications of the daily goods such as carbon ink in electronic field.