A random access method executed by a terminal device, comprising: transmitting a two-step random access request message to a network device; wherein a data part is carried in the two-step random access request message, and the data part is acquired through performing layer-two processing in accordance with layer-two configuration information, characterized in that when the layer-two configuration information comprises Packet Data Convergence Protocol, PDCP, layer configuration information, and the PDCP layer configuration information comprises indication information indicating that a default value of a PDCP sequence number, SN, size is a short PDCP SN size, the short PDCP SN size is a shortest one of all of the PDCP SN sizes, prior to transmitting the two-step random access request message to the network device, the random access method further comprises: numbering, through a PDCP layer entity, data delivered by a Service Data Adaption Protocol, SDAP, layer entity in accordance with the short PDCP SN size, and delivering the numbered data to a Radio Link Control, RLC, layer entity, to acquire the data part; and/or when the layer-two configuration information comprises the RLC layer configuration information and the RLC layer configuration information comprises indication information indicating that a default RLC transmission mode is a Transparent Mode, TM, mode, prior to transmitting the two-step random access request message to the network device, the random access method further comprises: directly delivering, through an RLC layer entity, data delivered by the PDCP layer entity to an MAC layer entity via a logic channel in the TM mode, to acquire the data part. transmitting a two-step random access request message to a network device; wherein a data part is carried in the two-step random access request message, and the data part is acquired through performing layer-two processing in accordance with layer-two configuration information, characterized in that when the layer-two configuration information comprises Packet Data Convergence Protocol, PDCP, layer configuration information, and the PDCP layer configuration information comprises indication information indicating that a default value of a PDCP sequence number, SN, size is a short PDCP SN size, the short PDCP SN size is a shortest one of all of the PDCP SN sizes, prior to transmitting the two-step random access request message to the network device, the random access method further comprises: numbering, through a PDCP layer entity, data delivered by a Service Data Adaption Protocol, SDAP, layer entity in accordance with the short PDCP SN size, and delivering the numbered data to a Radio Link Control, RLC, layer entity, to acquire the data part; and/or when the layer-two configuration information comprises the RLC layer configuration information and the RLC layer configuration information comprises indication information indicating that a default RLC transmission mode is a Transparent Mode, TM, mode, prior to transmitting the two-step random access request message to the network device, the random access method further comprises: directly delivering, through an RLC layer entity, data delivered by the PDCP layer entity to an MAC layer entity via a logic channel in the TM mode, to acquire the data part. numbering, through a PDCP layer entity, data delivered by a Service Data Adaption Protocol, SDAP, layer entity in accordance with the short PDCP SN size, and delivering the numbered data to a Radio Link Control, RLC, layer entity, to acquire the data part; and/or when the layer-two configuration information comprises the RLC layer configuration information and the RLC layer configuration information comprises indication information indicating that a default RLC transmission mode is a Transparent Mode, TM, mode, prior to transmitting the two-step random access request message to the network device, the random access method further comprises: directly delivering, through an RLC layer entity, data delivered by the PDCP layer entity to an MAC layer entity via a logic channel in the TM mode, to acquire the data part.