The invention relates to an energy-saving MAC and routing cross-layer method for a linear monitoring network. The method comprises that: all nodes are configured with a logic ID in advance according to the physical positions; the communication is initiated by an end node, the MAC protocol is realized based on a sleep wakeup mechanism, the wakeup method is group wakeup, the wakened nodes automatically judge whether to sleep or continuously monitor according to the ID in the received data and the directional information, and a routing layer automatically selects the next hop according to the last hop node information in the MAC layer data when the node selects the next hop node; the neighbor node can jump the hop to respond when the called node has no response; and the current node fuses all the past node data and transmits the data to the next stage so as to reduce the transmission of useless information and improve the efficiency of energy consumption. The method can be widely applied to the places of pipeline survey, road survey, fuel gas wireless network acquisition systems and the like, and has the advantages of saving the energy of the survey node, prolonging the life cycle of the node and effectively improving the work efficiency.